build: Set osx permissions in the dmg to make Gatekeeper happy

Github-Pull: bitcoin#7092
Rebased-From: 392d3c5

Makefile.am

@@ -111,7 +111,7 @@ $(APP_DIST_DIR)/Applications:
 $(APP_DIST_EXTRAS): $(APP_DIST_DIR)/$(OSX_APP)/Contents/MacOS/Bitcoin-Qt
 
 $(OSX_DMG): $(APP_DIST_EXTRAS)
-	$(GENISOIMAGE) -no-cache-inodes -D -l -probe -V "Bitcoin-Core" -no-pad -r -apple -o $@ dist
+	$(GENISOIMAGE) -no-cache-inodes -D -l -probe -V "Bitcoin-Core" -no-pad -r -dir-mode 0755 -apple -o $@ dist
 
 $(APP_DIST_DIR)/.background/$(OSX_BACKGROUND_IMAGE): contrib/macdeploy/$(OSX_BACKGROUND_IMAGE)
 	$(MKDIR_P) $(@D)