Add check for page_branch_in_footer.
Add check for page_branch_in_footer.

Without this check, footer.html is rendered for every page in the tree,
returning an empty string.

ZeroXn/mezzanine,molokov/mezzanine,molokov/mezzanine,industrydive/mezzanine,agepoly/mezzanine,ryneeverett/mezzanine,douglaskastle/mezzanine,webounty/mezzanine,gbosh/mezzanine,sjdines/mezzanine,webounty/mezzanine,agepoly/mezzanine,nikolas/mezzanine,dsanders11/mezzanine,stephenmcd/mezzanine,Cicero-Zhao/mezzanine,guibernardino/mezzanine,eino-makitalo/mezzanine,SoLoHiC/mezzanine,vladir/mezzanine,eino-makitalo/mezzanine,dekomote/mezzanine-modeltranslation-backport,damnfine/mezzanine,gradel/mezzanine,gradel/mezzanine,viaregio/mezzanine,jjz/mezzanine,jerivas/mezzanine,jjz/mezzanine,christianwgd/mezzanine,mush42/mezzanine,emile2016/mezzanine,ryneeverett/mezzanine,wbtuomela/mezzanine,nikolas/mezzanine,mush42/mezzanine,wrwrwr/mezzanine,emile2016/mezzanine,PegasusWang/mezzanine,adrian-the-git/mezzanine,industrydive/mezzanine,promil23/mezzanine,readevalprint/mezzanine,frankchin/mezzanine,viaregio/mezzanine,scarcry/snm-mezzanine,wyzex/mezzanine,frankier/mezzanine,adrian-the-git/mezzanine,dekomote/mezzanine-modeltranslation-backport,frankier/mezzanine,dustinrb/mezzanine,industrydive/mezzanine,wbtuomela/mezzanine,spookylukey/mezzanine,geodesign/mezzanine,spookylukey/mezzanine,biomassives/mezzanine,stbarnabas/mezzanine,wrwrwr/mezzanine,dsanders11/mezzanine,dekomote/mezzanine-modeltranslation-backport,orlenko/sfpirg,sjuxax/mezzanine,batpad/mezzanine,guibernardino/mezzanine,christianwgd/mezzanine,emile2016/mezzanine,jjz/mezzanine,theclanks/mezzanine,batpad/mezzanine,Kniyl/mezzanine,biomassives/mezzanine,mush42/mezzanine,wyzex/mezzanine,AlexHill/mezzanine,promil23/mezzanine,orlenko/plei,orlenko/sfpirg,cccs-web/mezzanine,damnfine/mezzanine,Skytorn86/mezzanine,dsanders11/mezzanine,Skytorn86/mezzanine,spookylukey/mezzanine,geodesign/mezzanine,wyzex/mezzanine,Cicero-Zhao/mezzanine,SoLoHiC/mezzanine,douglaskastle/mezzanine,sjdines/mezzanine,scarcry/snm-mezzanine,gradel/mezzanine,agepoly/mezzanine,ryneeverett/mezzanine,SoLoHiC/mezzanine,orlenko/sfpirg,frankchin/mezzanine,saintbird/mezzanine,sjuxax/mezzanine,theclanks/mezzanine,sjuxax/mezzanine,ZeroXn/mezzanine,vladir/mezzanine,cccs-web/mezzanine,joshcartme/mezzanine,frankier/mezzanine,jerivas/mezzanine,webounty/mezzanine,Cajoline/mezzanine,orlenko/plei,PegasusWang/mezzanine,nikolas/mezzanine,eino-makitalo/mezzanine,scarcry/snm-mezzanine,dovydas/mezzanine,gbosh/mezzanine,tuxinhang1989/mezzanine,fusionbox/mezzanine,dovydas/mezzanine,biomassives/mezzanine,damnfine/mezzanine,dustinrb/mezzanine,saintbird/mezzanine,geodesign/mezzanine,ZeroXn/mezzanine,AlexHill/mezzanine,wbtuomela/mezzanine,stbarnabas/mezzanine,viaregio/mezzanine,vladir/mezzanine,sjdines/mezzanine,molokov/mezzanine,adrian-the-git/mezzanine,tuxinhang1989/mezzanine,stephenmcd/mezzanine,readevalprint/mezzanine,orlenko/plei,dustinrb/mezzanine,joshcartme/mezzanine,Kniyl/mezzanine,theclanks/mezzanine,fusionbox/mezzanine,Skytorn86/mezzanine,dovydas/mezzanine,jerivas/mezzanine,Cajoline/mezzanine,saintbird/mezzanine,douglaskastle/mezzanine,christianwgd/mezzanine,promil23/mezzanine,gbosh/mezzanine,Cajoline/mezzanine,stephenmcd/mezzanine,joshcartme/mezzanine,readevalprint/mezzanine,tuxinhang1989/mezzanine,Kniyl/mezzanine,PegasusWang/mezzanine,frankchin/mezzanine