rubocop: fixed "Favor modifier if usage when having a single-line body"

.rubocop.yml

@@ -67,11 +67,6 @@ Style/CommentAnnotation:
 Style/Documentation:
   Enabled: false
 
-# Offense count: 2
-# Configuration parameters: MaxLineLength.
-Style/IfUnlessModifier:
-  Enabled: false
-
 # Offense count: 12
 # Cop supports --auto-correct.
 # Configuration parameters: EnforcedStyle, SupportedStyles.

src/lib/registration/ui/addon_selection_dialog.rb

@@ -119,9 +119,8 @@ def addon_checkbox(addon, extra_spacing)
 
         # usability help. If addon depends on something, then we get it
         # immediatelly after parent, so indent it slightly, so it is easier visible
-        if addon.depends_on
-          checkbox = HBox(HSpacing(2.5), checkbox)
-        end
+        checkbox = HBox(HSpacing(2.5), checkbox) if addon.depends_on
+
         res = [checkbox]
         # add extra spacing when there are just few addons, in GUI always
         res << VSpacing(0.7) if extra_spacing
@@ -163,9 +162,7 @@ def handle_dialog
       end
 
       def handle_next_button
-        if !supported_addon_count?
-          return nil
-        end
+        return nil unless supported_addon_count?
 
         log.info "Selected addons: #{Addon.selected.map(&:name)}"