Fix stackrc os-resource-classes typo

Attempting to use LIBS_FROM_GIT="ALL" results in a failure
due to a typo in stackrc for os-resource-classes repo.

  Cloning into '/opt/stack/os-resource-classes'...
  fatal: protocol ':-https' is not supported
  <snip>
  [ERROR] /opt/stack/devstack/functions-common:629 git call failed: [git clone :-https://opendev.org/openstack/os-resource-classes.git /opt/stack/os-resource-classes --branch master]

Remove the extraneous '='.

Change-Id: I21f86324dc15fe808b38e366f7af18c96fd3890c
1 file changed