Fix spelling errors in code comments

Reported-by: Jens Schleusener <Jens.Schleusener@fossies.org>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

url.c

@@ -5,7 +5,7 @@ int is_urlschemechar(int first_flag, int ch)
 {
 	/*
 	 * The set of valid URL schemes, as per STD66 (RFC3986) is
-	 * '[A-Za-z][A-Za-z0-9+.-]*'. But use sightly looser check
+	 * '[A-Za-z][A-Za-z0-9+.-]*'. But use slightly looser check
 	 * of '[A-Za-z0-9][A-Za-z0-9+.-]*' because earlier version
 	 * of check used '[A-Za-z0-9]+' so not to break any remote
 	 * helpers.