Incorrect error message in UI during uploading large files

[Ekaterina Chernova]

1) login as admin user
2) go to Manage -> package definitions
3) upload any file (zip archive) greater than 500 Mb

actual result:
It is restricted to upload files larger than 5<django.utils.functional.__proxy__ object at 0x7fdadddba3d0>.

Need to fix this error message

[Timur Nurlygayanov (tnurlygayanov)]

Fix proposed in https://review.openstack.org/#/c/89329

[Openstack Gerrit (openstack-gerrit)]

Reviewed: https://review.openstack.org/89329
Committed: https://git.openstack.org/cgit/stackforge/murano-dashboard/commit/?id=9dc5907b846819ed7f9d3fcca75c82e891615917
Submitter: Jenkins
Branch: master

commit 9dc5907b846819ed7f9d3fcca75c82e891615917
Author: TimurNurlygayanov <email address hidden>
Date: Mon Apr 21 14:37:10 2014 +0400

    Fixed issue with error message

    Need to remove _() for 'MB', because we will translate
    this in other _() function.

    Change-Id: I0595ee7b3efb480707410767a3608335e2f795ae
    Closes-Bug: #1305019