debian/control: Remove gtk-doc-tools build dependency
debian/control: Remove gtk-doc-tools build dependency

Change-Id: I3fa2e408827c5a53a97cccd52ccb5c9d55178765

shelsonjava/kms-elements,TribeMedia/kms-elements,TribeMedia/kms-elements,Kurento/kms-elements,shelsonjava/kms-elements,Kurento/kms-elements,Kurento/kms-elements,TribeMedia/kms-elements,shelsonjava/kms-elements