TSG S2: fix issues with killing the bandit leader first

- The peasants told Deoran to go for the already defeated bandit leader.
- The pesants were useless at that time - they are now instead spawned when
  defeating the bandit leader or when Deoran arrives, whatever happens first.
  They may still have a fight with remaining bandits – or provoke their attack.
- The dialogue when reaching the citadel after having defeated the bandits got a
  slight change, to better switch to the victory dance event.

(issue #1954)

[ci skip]

data/campaigns/The_South_Guard/scenarios/02_Proven_by_the_Sword.cfg

@@ -336,27 +336,28 @@
             speaker=Minister Hylas
             message= _ "Alas, Sir Loris will find no relief now. He is buried northwest of the city where he fell. For weeks we warned him of the new power of these bandits. And yet he would never lead his men against them until their strength had waxed and ours waned."
         [/message]
-        [message]
-            speaker=Deoran
-            image=portraits/deoran-sad.png
-            message= _ "It grieves me to learn of his death, foolish though he may have been! Now, though, there are more pressing matters. Rise, men of Wesnoth! We must drive these bandits from our city!"
-        [/message]
-
-        {NAMED_LOYAL_UNIT 1 Peasant 18 15 (Ufes) (_"Ufes")}
-        {NAMED_LOYAL_UNIT 1 Peasant 18 16 (Joran) (_"Joran")}
-        {NAMED_LOYAL_UNIT 1 Peasant 19 18 (Makees) (_"Makees")}
-        {NAMED_LOYAL_UNIT 1 Peasant 20 18 (Tyborg) (_"Tyborg")}
-
-        [message]
-            speaker=Ufes
-            message= _ "We will do our best to hold the city — you lead your men across the river and kill the bandit leader!"
-        [/message]
 
         [if]
             [have_unit]
                 id=Urza Nalmath
             [/have_unit]
             [then]
+                [message]
+                    speaker=Deoran
+                    image=portraits/deoran-sad.png
+                    message= _ "It grieves me to learn of his death, foolish though he may have been! Now, though, there are more pressing matters. Rise, men of Wesnoth! We must drive these bandits from our city!"
+                [/message]
+
+                {NAMED_LOYAL_UNIT 1 Peasant 18 15 (Ufes) (_"Ufes")}
+                {NAMED_LOYAL_UNIT 1 Peasant 18 16 (Joran) (_"Joran")}
+                {NAMED_LOYAL_UNIT 1 Peasant 19 18 (Makees) (_"Makees")}
+                {NAMED_LOYAL_UNIT 1 Peasant 20 18 (Tyborg) (_"Tyborg")}
+
+                [message]
+                    speaker=Ufes
+                    message= _ "We will do our best to hold the city — you lead your men across the river and kill the bandit leader!"
+                [/message]
+
                 [show_objectives][/show_objectives]
 
                 [set_recruit]
@@ -386,6 +387,12 @@
                 [/gold]
             [/then]
             [else]
+                [message]
+                    speaker=Deoran
+                    image=portraits/deoran-sad.png
+                    message= _ "It grieves me to learn of his death, foolish though he may have been! At least we managed to defeat some of these bandits here and now. What else happened?"
+                [/message]
+                # Peasants have already been spawned.
                 [fire_event]
                     name=victory dance
                 [/fire_event]
@@ -598,6 +605,35 @@
                     name=victory dance
                 [/fire_event]
             [/then]
+            [else]
+                {NAMED_LOYAL_UNIT 1 Peasant 18 15 (Ufes) (_"Ufes")}
+                {NAMED_LOYAL_UNIT 1 Peasant 18 16 (Joran) (_"Joran")}
+                {NAMED_LOYAL_UNIT 1 Peasant 19 18 (Makees) (_"Makees")}
+                {NAMED_LOYAL_UNIT 1 Peasant 20 18 (Tyborg) (_"Tyborg")}
+                [message]
+                    speaker=Ufes
+                    message= _ "The bandits are defeated!"
+                [/message]
+                [if]
+                    [have_unit]
+                        side=2
+                        count=0-2
+                    [/have_unit]
+                    [then]
+                        [message]
+                            speaker=Makees
+                            message= _ "Westin is safe again."
+                        [/message]
+                    [/then]
+                    [else]
+                        [message]
+                            speaker=Makees
+                            message= _ "Westin will soon be safe again."
+                        [/message]
+                    [/else]
+                [/if]
+                [show_objectives][/show_objectives]
+            [/else]
         [/if]
     [/event]
 
@@ -646,6 +682,7 @@
 
     [event]
         name=victory
+
         [disallow_recruit]
             type=Peasant
             side=1