let ast_say_digit_str say 'minus' preceding negative numbers (bug #3948)

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@5384 65c4cc65-6c06-0410-ace0-fbb531ad65f3

say.c

@@ -54,6 +54,9 @@ int ast_say_digit_str(struct ast_channel *chan, const char *fn2, const char *int
 			case ('#'):
 				snprintf(fn, sizeof(fn), "digits/pound");
 				break;
+			case ('-'):
+				snprintf(fn, sizeof(fn), "digits/minus");
+				break;
 			default:
 				if((fn2[num] >= '0') && (fn2[num] <= '9')){ /* Must be in {0-9} */
 					snprintf(fn, sizeof(fn), "digits/%c", fn2[num]);