Add check first if need to change permissions, like in fixSetGroupID.

On linux when download user and sickbeard user are not the same,
moving files will result in download user still owning the files.
When SickBeard tries to chmod permissions it results in error,
because only root or owner are allowed to do this.
Check first if need to change permissions, like in fixSetGroupID.
If same do nothing.

sickbeard/helpers.py

@@ -436,12 +436,16 @@ def chmodAsParent(childPath):
         return
     
     parentMode = stat.S_IMODE(os.stat(parentPath)[stat.ST_MODE])
+    childPath_mode = stat.S_IMODE(os.stat(childPath)[stat.ST_MODE])
 
     if ek.ek(os.path.isfile, childPath):
         childMode = fileBitFilter(parentMode)
     else:
         childMode = parentMode
 
+    if childPath_mode == childMode:
+        return
+
     try:
         ek.ek(os.chmod, childPath, childMode)
         logger.log(u"Setting permissions for %s to %o as parent directory has %o" % (childPath, childMode, parentMode), logger.DEBUG)