[Tizen][Runtime] Do not require to set the application version in config.xml.

On Tizen platform, a Tizen wgt web application is not required to have a
'version' field in config.xml, the Crosswalk runtime should follow this behavior.

BUG=XWALK-2220
Merge pull request #2278 from takethathe/not_check_version

[Tizen][Runtime] Do not require to set the application version in config.xml