tools: do not leak uri in disconnect handler

Commit 035947eb introduced a call to virConnectGetURI
without a matching free() in virshCatchDisconnect.

Also fix vshAdmCatchDisconnect where it was copied by
commit 6dd7e42d.

https://bugzilla.redhat.com/show_bug.cgi?id=1303891

tools/virsh.c

@@ -124,6 +124,7 @@ virshCatchDisconnect(virConnectPtr conn,
             break;
         }
         vshError(ctl, _(str), NULLSTR(uri));
+        VIR_FREE(uri);
 
         if (error) {
             virSetError(error);

tools/virt-admin.c

@@ -92,6 +92,7 @@ vshAdmCatchDisconnect(virAdmConnectPtr conn ATTRIBUTE_UNUSED,
     }
 
     vshError(ctl, _(str), NULLSTR(uri));
+    VIR_FREE(uri);
 
     if (error) {
         virSetError(error);