OS X: reintroduce LSUIElement in Info.plist

cmake/modules/MacOSXBundleInfo.plist.in

@@ -4,7 +4,9 @@
 <dict>
         <key>NSPrincipalClass</key>
 	<string>NSApplication</string>
-        <key>CFBundleDevelopmentRegion</key>
+	<key>LSUIElement</key>
+	<true/>
+	<key>CFBundleDevelopmentRegion</key>
         <string>English</string>
         <key>CFBundleExecutable</key>
         <string>owncloud</string>