Fix emacs doc by removing empty argument to merlin
Fix emacs doc by removing empty argument to merlin

An empty argument "" is considered invalid in merlin

chenglou/reason,yunxing/reason,cristianoc/reason,chenglou/reason,facebook/reason,let-def/reason,cristianoc/reason,ak3n/reason,ak3n/reason,ak3n/reason,cristianoc/reason,facebook/reason,let-def/reason,yunxing/reason,chenglou/reason,let-def/reason,facebook/reason,yunxing/reason,yunxing/reason,ak3n/reason