Stop treating OpenProjectFiles failure like a fatal error

There is no need to try to bail out if this call fails,
and the bail-out was wiping out the app settings.

Fixes https://gitlab.com/kicad/code/kicad/-/issues/13427

common/single_top.cpp

@@ -408,22 +408,7 @@ bool PGM_SINGLE_TOP::OnPgmInit()
             fileArgs[0] = argv1.GetFullPath();
         }
 
-        // Use the KIWAY_PLAYER::OpenProjectFiles() API function:
-        if( !frame->OpenProjectFiles( fileArgs ) )
-        {
-            // OpenProjectFiles() API asks that it report failure to the UI.
-            // Nothing further to say here.
-
-            // We've already initialized things at this point, but wx won't call OnExit if
-            // we fail out. Call our own cleanup routine here to ensure the relevant resources
-            // are freed at the right time (if they aren't, segfaults will occur).
-            OnPgmExit();
-
-            // Fail the process startup if the file could not be opened,
-            // although this is an optional choice, one that can be reversed
-            // also in the KIFACE specific OpenProjectFiles() return value.
-            return false;
-        }
+        frame->OpenProjectFiles( fileArgs );
     }
 
     return true;