builtin-revert.c: typofix

Signed-off-by: NStephan Beyer <s-beyer@gmx.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

builtin-revert.c

@@ -180,7 +180,7 @@ static void set_author_ident_env(const char *message)
 			email++;
 			timestamp = strchr(email, '>');
 			if (!timestamp)
-				die ("Could not extract author email from %s",
+				die ("Could not extract author time from %s",
 					sha1_to_hex(commit->object.sha1));
 			*timestamp = '\0';
 			for (timestamp++; *timestamp && isspace(*timestamp);