Catch an exception when initializing JSWidget
[Issue#] TWEB-427
[Feature] There can be exception when JSWidget tries to initializes
preferences object.
[Cause] WebProcess gets SIGABORT when initialize fails.
[Solution] Catch an exception. Allow to run normally.
[Verification] Run iframes.wgt widget from wrt-extra repository.
WebProcess should not fail when counter in widget hits ~160.
Verification requires patch from wrt-commons:
http://tizendev.org/gerrit/15863
Change-Id: Iaf9f5963d4a84cd9d518a7db1d57d350e8f64d46