updated for version 7.3.506

Problem:    GTK gives an error when selecting a non-existent file.
Solution:   Add a handler to avoid the error. (Christian Brabandt)

src/version.c

@@ -714,6 +714,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    506,
 /**/
     505,
 /**/