bisect--helper: add space between colon and following sentence

Add missing space between colon sentence (`bisect-run failed:`) and the
following sentence (`git bisect--helper --bisect-state`).

Fixes: d1bbbe4 (bisect--helper: reimplement `bisect_run` shell
function in C, 2021-09-13)
Signed-off-by: Bagas Sanjaya <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: bagasme

builtin/bisect--helper.c

@@ -1157,7 +1157,7 @@ static int bisect_run(struct bisect_terms *terms, const char **argv, int argc)
 			printf(_("bisect found first bad commit"));
 			res = BISECT_OK;
 		} else if (res) {
-			error(_("bisect run failed:'git bisect--helper --bisect-state"
+			error(_("bisect run failed: 'git bisect--helper --bisect-state"
 			" %s' exited with error code %d"), args.v[0], res);
 		} else {
 			continue;