fix(typo): initial variable during input parsing

This was probably a typo since the `w` gets set again during
`detectOneMsg` it wouldn't make sense to initially set it to `07` and it
makes the code confusing.

Fixes: a154847 (feat: extended Coordinates mouse reporting & additional buttons support (#594))

key.go

@@ -581,7 +581,7 @@ loop:
 		canHaveMoreData := numBytes == len(buf)
 
 		var i, w int
-		for i, w = 0, 07; i < len(b); i += w {
+		for i, w = 0, 0; i < len(b); i += w {
 			var msg Msg
 			w, msg = detectOneMsg(b[i:], canHaveMoreData)
 			if w == 0 {