fixes issue where STATIC_URL was overwritten without git.revision

fixes this commit - https://github.com/edx/edx-platform/commit/5ec77010e3bc0303cdb06ebf32e806936fd36ce6
adding slash
convert STATIC_URL to ascii
STATIC_URL_BASE for lms config
Merge pull request #1713 from edx/jarv/fix-static-url

fixes issue where STATIC_URL was overwritten without git.revision