[1.1, 1.2] sfDoctrineGuardPlugin: fixes #4583 - issue with catching wrong exception
[1.1, 1.2] sfDoctrineGuardPlugin: fixes #4583 - issue with catching wrong exception


git-svn-id: e6180648f1438032975755a03660179a2fce9ff1@12076 ee427ae8-e902-0410-961c-c3ed070cd9f9

maxim-oleinik/sfDoctrineGuardPlugin,nixilla/sfDoctrineGuardPlugin,pixelfusion/sfDoctrineGuardPlugin