Fixed "Jump to File System" not working.

Author: akitisa-epic

python/tk_unreal/unreal_sg_engine.py

@@ -5,6 +5,8 @@
 import unreal
 import sgtk.platform
 import config
+import sys
+import os
 
 unreal.log("Loading Shotgun Engine for Unreal from {}".format(__file__))