server: reorder dialback matching to allow empty keys
server: reorder dialback matching to allow empty keys

No idea if that makes sense but ejabberd sent this in an erroneous
situation. :-)

qbit/node-xmpp,samuelagm/ltx,xmppjs/xmpp.js,fritx/ltx,agebrock/node-xmpp,agebrock/node-xmpp,ggozad/node-xmpp,fritx/ltx,node-xmpp/node-xmpp,xmppjs/xmpp.js,WeBest/node-xmpp,stliu/node-xmpp,node-xmpp/ltx,node-xmpp/node-xmpp,swissmanu/ltx,tempbottle/node-xmpp,ggozad/node-xmpp,bentaber/ltx,qbit/node-xmpp,eelcocramer/node-xmpp