Fixed a small bug where the --hostname argument to lnt create was not being interpolated into the wsgi script.

This looks like just a careless mistake where the interpolation pattern was not
placed in correctly.

git-svn-id: https://llvm.org/svn/llvm-project/lnt/trunk@197227 91177308-0d34-0410-b5e6-96231b3b80d8