Some operating system incorrectly detect javascript mime-type

Turns out django cherrypy server on SLES uses python "mimetypes" module to detect file type. Eventually the mimetype detection on SLES fails to detect javascript as "appication/javascript"
[root@ranade-510-1 js]# lsb_release -a
Description: CentOS release 6.6 (Final)
[root@ranade-510-1 js]# python -c 'import mimetypes; print mimetypes.guess_type("./knockout.min.fa8662c7a841.js")'
('text/javascript', None)
*[root@ranade-510-1 js]# cat /etc/mime.types | grep "js$"
text/javascript js*

ranade-sles11sp4-511-1 # lsb_release -a
Description: SUSE Linux Enterprise Server 11 (x86_64)
ranade-sles11sp4-511-1 # python -c 'import mimetypes; print mimetypes.guess_type("./knockout.min.fa8662c7a841.js")'
('text/x-js', None)
*ranade-sles11sp4-511-1 # cat /etc/mime.types | grep "js$"
application/javascript js
text/x-js js*

The wrong mimetype could not accepted by local browser(when secure_content_type_nosniff=true) which throws 'MIME type ('text/x-js') is not executable error.
But if we use "Load Balancer" port then load balancer configuration force mime-type "application/javascript" for "js" files.
I have implemented fix in django code where if user uses "django" port then django code will force mime-type "application/javscript" for ".js" files.