parser yang BUGFIX support for CRLF newlines

Fixes #1467
diff --git a/src/parser_yang.c b/src/parser_yang.c
index 6e38e2c..2647764 100644
--- a/src/parser_yang.c
+++ b/src/parser_yang.c
@@ -689,6 +689,12 @@
             /* skip whitespaces (optsep) */
             ctx->indent += Y_TAB_SPACES;
             break;
+        case '\r':
+            /* possible CRLF endline */
+            if (ctx->in->current[1] == '\n') {
+                break;
+            }
+            /* fallthrough */
         default:
             /* either a keyword start or an invalid character */
             goto keyword_start;