macosx/QuincyKit: fix a few compilation warnings

modules/gui/macosx/BWQuincyManager.h

@@ -94,13 +94,11 @@ typedef enum CrashReportStatus {
 
 @protocol BWQuincyManagerDelegate <NSObject>
 
-@required
+@optional
 
 // Invoked once the modal sheets are gone
 - (void) showMainApplicationWindow;
 
-@optional
-
 // Return the description the crashreport should contain, empty by default. The string will automatically be wrapped into <[DATA[ ]]>, so make sure you don't do that in your string.
 -(NSString *) crashReportDescription;
 
@@ -164,6 +162,7 @@ typedef enum CrashReportStatus {
 
 - (NSString *) applicationName;
 - (NSString *) applicationVersionString;
+- (void)setApplicationVersion:(NSString *)appVersion;
 - (NSString *) applicationVersion;
 
 @end

modules/gui/macosx/intf.m

@@ -592,7 +592,7 @@ audio_output_t *getAout(void)
 #pragma mark -
 #pragma mark Private
 
-@interface VLCMain ()
+@interface VLCMain () <BWQuincyManagerDelegate>
 - (void)removeOldPreferences;
 @end