Updated javascript mimetypes (#9347)

+ Updated js to text/javascript
 + added mjs extension

Signed-off-by: gregw <gregw@webtide.com>

jetty-http/src/main/resources/org/eclipse/jetty/http/mime.properties

@@ -59,7 +59,7 @@ jpe=image/jpeg
 jp2=image/jpeg2000
 jpeg=image/jpeg
 jpg=image/jpeg
-js=application/javascript
+js=text/javascript
 json=application/json
 jsp=text/html
 kar=audio/midi
@@ -73,6 +73,7 @@ mesh=model/mesh
 mid=audio/midi
 midi=audio/midi
 mif=application/vnd.mif
+mjs=text/javascript
 mol=chemical/x-mdl-molfile
 mov=video/quicktime
 movie=video/x-sgi-movie