Fix number suffix detection

Allow a number not to have a suffix. This broke when adding the
suffixes.

Signed-off-by: Carlos Martín Nieto <cmn@elego.de>

src/config.c

@@ -394,6 +394,8 @@ int git_config_get_long(git_config *cfg, const char *name, long int *out)
 		return GIT_EINVALIDTYPE;
 
 	switch (*num_end) {
+	case '\0':
+		break;
 	case 'k':
 		num *= 1024;
 		break;