Room details: fix timestamp display on iOS > 8
Room details: fix timestamp display on iOS > 8

vector-im/vector-ios,vector-im/riot-ios,vector-im/vector-ios,vector-im/riot-ios,vector-im/riot-ios,vector-im/riot-ios,matrix-org/matrix-ios-console,matrix-org/matrix-ios-console,vector-im/vector-ios,vector-im/riot-ios,vector-im/riot-ios