Highlight .mjs as javascript

Bug: Issue 11020
Change-Id: I42927f81206df10347a266b4778e813f8c5c96d2
diff --git a/resources/com/google/gerrit/server/mime/mime-types.properties b/resources/com/google/gerrit/server/mime/mime-types.properties
index 8159ac1..6fbd341 100644
--- a/resources/com/google/gerrit/server/mime/mime-types.properties
+++ b/resources/com/google/gerrit/server/mime/mime-types.properties
@@ -124,7 +124,7 @@
 mbox = application/mbox
 md = text/x-markdown
 mirc = text/mirc
-mjs = text/x-mjs
+mjs = text/javascript
 mkd = text/x-markdown
 ml = text/x-ocaml
 mli = text/x-ocaml