virnetsocket: Pass KRB5CCNAME env variable

So we can allow GSSAPI authentication for ssh.
Signed-off-by: NMatthias Witte <witte@netzquadrat.de>

AUTHORS

@@ -194,6 +194,7 @@ Patches have also been contributed by:
   Steve Hodgson        <shodgson@solarflare.com>
   Xu He Jie            <xuhj@linux.vnet.ibm.com>
   Lei Li               <lilei@linux.vnet.ibm.com>
+  Matthias Witte       <witte@netzquadrat.de>
 
   [....send patches to get your name here....]
 

src/rpc/virnetsocket.c

@@ -615,6 +615,7 @@ int virNetSocketNewConnectSSH(const char *nodename,
 
     cmd = virCommandNew(binary ? binary : "ssh");
     virCommandAddEnvPassCommon(cmd);
+    virCommandAddEnvPass(cmd, "KRB5CCNAME");
     virCommandAddEnvPass(cmd, "SSH_AUTH_SOCK");
     virCommandAddEnvPass(cmd, "SSH_ASKPASS");
     virCommandAddEnvPass(cmd, "DISPLAY");