Update keycodemapdb submodule for python2 compat fixes

There were a few bugs in keycodemap tool that broke it
when run on python circa 2.7.5 or older, which affected
RHEL builds.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

keycodemapdb @ 7bf5710b

-Subproject commit bd754b861e7de5c7919aa249a975913cb207b85d
+Subproject commit 7bf5710b22aa8d58b7eeaaf3dc6960c26cade4f0