fixing a no-field error that gets shown

Hi @nadavfima I'm been experimenting with the application and integrating to an existing ABS-based app, however, eclipse/android had trouble building it because it tried to inflate a non existent field (`R.id.placeholder`), I know it is in one the res xml files but I have no idea why it is not visible, perhaps the scope of access just plays me..

ref: http://stackoverflow.com/questions/16204667/nosuchfielderror-on-findviewbyid

Disabling the mHeader (which seems to be unused seems to solve the error)