Prevent accidental deletion of home directory in Terminal Panel

The protection against unwanted execution of "rm -rf" when changing the
directory while entering the command did not work if there was never any
automatic "cd" command sent to the terminal before.

This patch ensures that Terminal Panel's member m_clearTerminal is
false after the initialization of the panel, such that the protection is
effective after that.

BUG: 316300
FIXED-IN: 4.10.2
REVIEW: 109431