Fixed silent crash, when viewer/composer opens

Fixed silent crash, when viewer/composer opens

[Title] When viewer/composer open, silent crash occurs
[Issue#] TD-9621
[Problem] When user tries to open a mail with html page in email application, silent crash occurs
[Cause] Since html content of email contains a sub resource url with path not having file read permissions,
message becomes invalid, hence UI process terminates.
[Solution] Given universal file read permissions in case of ewk_view_contents_set called from the application
as the same thing happening in loading file:///<url path> type of urls in browser application.
[Developer] Raveendra Karu (r.karu@samsung.com)