Replace deprecated NSApplication beginSheet: message in -[AMSProgressBar showAsSheetForWindow:] (not that it seems to ever be called anyways)

Author: undecoded-coder

trunk/AMSProgressBar/AMSProgressPanel.m

@@ -328,11 +328,7 @@ - (void) showAsSheetForWindow:(NSWindow *)parentWindow
 self.startTime = [NSDate date]; //right now
 runningAsSheet = YES;
 
-[NSApp beginSheet:dialogWindow
- modalForWindow:parentWindow 
-modalDelegate:self 
- didEndSelector:nil
- contextInfo:nil ];
+[[NSApp mainWindow] beginSheet:dialogWindow completionHandler:nil];
 }