BGM play prefab, enable loop option as default.

Author: jcs090218

Assets/Resources/JCSUnity_Resources/Sound/JCS_BGMPlayer.prefab

@@ -55,7 +55,7 @@ AudioSource:
   m_PlayOnAwake: 1
   m_Volume: 1
   m_Pitch: 1
-  Loop: 0
+  Loop: 1
   Mute: 0
   Spatialize: 0
   SpatializePostEffects: 0