Remove broken JSch check

The current check requires ANT_HOME/lib to contain jsch-0.1.48. There are
however other places, like .ant/lib where you can place the jar also. 
Additionally the build agents in TeamCity seems to wipe ANT_HOME/lib 
every now and then, which makes this a bad place to add extra jars.

Change-Id: I83b8e0612e72d422d4341fc68b1ab6a0c98848a5