Bug 1492: Installer started by unprivileged user shows warning about an incomplete translation again after elevation to administrator privileges

https://winscp.net/tracker/1492
(cherry picked from commit ab648ecee288e00616b1af6da6f69bf8028fc08e)

Source commit: d8e68f7db476ff91f5fe56fbe8fd75e7e9df6ac2

deployment/winscpsetup.iss

@@ -982,12 +982,6 @@ begin
     PrevVersion := Copy(PrevVersion, 1, 5);
   end;
 
-  Completeness := LanguageCompleteness(ActiveLanguage);
-  if (Completeness < 100) and (not WizardSilent) then
-  begin
-    ShowMessage(FmtMessage(CustomMessage('IncompleteTranslation'), [IntToStr(Completeness)]));
-  end;
-
   ProcessMissingTranslations(@CollectNames);
 
   WizardForm.KeyPreview := True;
@@ -1053,6 +1047,13 @@ begin
     end;
   end;
 
+  // Only after elevating, not to show the message twice
+  Completeness := LanguageCompleteness(ActiveLanguage);
+  if (Completeness < 100) and (not WizardSilent) then
+  begin
+    ShowMessage(FmtMessage(CustomMessage('IncompleteTranslation'), [IntToStr(Completeness)]));
+  end;
+
   // installation type page
 
   SetupTypePage := CreateCustomPage(wpLicense,