fixed js error in annotations if no graph available


git-svn-id: http://dev.piwik.org/svn/trunk@7735 59fd770c-687e-43c8-a1e3-f5a4ff64c105
Fixing build, hopefully.


git-svn-id: http://dev.piwik.org/svn/trunk@7736 59fd770c-687e-43c8-a1e3-f5a4ff64c105
Fixing build, again, hopefully.


git-svn-id: http://dev.piwik.org/svn/trunk@7737 59fd770c-687e-43c8-a1e3-f5a4ff64c105