ref-filter: Do not abruptly die when using the 'lstrip=<N>' option

Currently when we use the 'lstrip=<N>' option, if 'N' is greater than
the number of components available in the refname, we abruptly end
program execution by calling die().

This behavior is undesired since a single refname with few components
could end program execution. To avoid this, return an empty string
whenever the value 'N' is greater than the number of components
available, instead of calling die().

Signed-off-by: Karthik Nayak <Karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

ref-filter.c

@@ -1099,8 +1099,7 @@ static const char *lstrip_ref_components(const char *refname, unsigned int len)
 	while (remaining) {
 		switch (*start++) {
 		case '\0':
-			die(_("ref '%s' does not have %ud components to :lstrip"),
-			    refname, len);
+			return "";
 		case '/':
 			remaining--;
 			break;