[dbmanager] re-enable line number again (followup 5e36de7 and d9f934f)

Author: jef-n

python/plugins/db_manager/dlg_sql_window.py

@@ -70,6 +70,7 @@ def __init__(self, iface, db, parent=None):
 
         self.editSql.setFocus()
         self.editSql.setVerticalScrollBarPolicy(Qt.ScrollBarAsNeeded)
+        self.editSql.setMarginVisible(True)
         self.initCompleter()
 
         # allow copying results

python/plugins/db_manager/sqledit.py

@@ -177,3 +177,6 @@ def initLexer(self):
 
     def lexer(self):
         return self.mylexer
+
+    def setMarginVisible(self, visible):
+        pass