add default branding parameter for email notifs
add default branding parameter for email notifs

martindale/vector,vector-im/vector-web,KentShikama/vector-web,vector-im/riot-web,vector-im/vector-web,KentShikama/vector-web,KentShikama/vector-web,vector-im/riot-web,vector-im/vector-web,vector-im/riot-web,vector-im/vector-web,KentShikama/vector-web,vector-im/vector-web,KentShikama/vector-web,vector-im/riot-web,martindale/vector,KentShikama/vector-web,vector-im/riot-web,vector-im/riot-web