Change Cache Telnet success message

Change the CMake status message that prints out the success of the Telnet
connection to not just print out the return code, but print out  "Telnet
Connection Established" if the script returns sucessfully.

OSEHRA-Id: http://issues.osehra.org/browse/OAT-146
Change-Id: If41479861ceb1a7af954a9ba096a7e7f98c6f5aa