use arg_split(...strict=False) in module_completer

IPython/core/completerlib.py

@@ -236,7 +236,7 b' def module_completer(self,event):'
 def magic_run_completer(self, event):
     """Complete files that end in .py or .ipy for the %run command.
     """
-    comps = arg_split(event.line)
+    comps = arg_split(event.line, strict=False)
     relpath = (len(comps) > 1 and comps[-1] or '').strip("'\"")
 
     #print("\nev=", event)  # dbg