glusterd/geo-rep: Fix glusterd crash in non-originator slave node.

Problem: glusterd crashes in non-originator slave node during geo-rep
         create push-pem.

Cause: In glusterd_op_copy_file, the value of the key "common_pem_contents"
       is freed explicitly even after dict_set is successful when it is
       taken cared by dict_free.

Solution: Free only in failure cases before dict_set.

BUG: 1159210
Change-Id: I726f923915fc24de6588469c27f2cc996c20c59d
Reviewed-On: http://review.gluster.org/9018/
Signed-off-by: Kotresh HR <khiremat@redhat.com>
Reviewed-on: http://review.gluster.org/9026
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Venky Shankar <vshankar@redhat.com>
Tested-by: Venky Shankar <vshankar@redhat.com>