Remove wrong spaces in nova option

vncserver_ proxyclient_ address should be vncserver_proxyclient_address

Change-Id: If3e39c8e6c162bc60ee75c410a708c1d2f51ca9f
Closes-Bug: #1308553
backport: havana
(cherry picked from commit 0016e2657d95c77acc584b3bbdb9d8ea87b540a1)
Merge "Remove wrong spaces in nova option" into stable/havana