Don't try to show a menu for multipolygons
Don't try to show a menu for multipolygons

We haven't implemented relation deletion yet, so there
aren't any operations to perform.

Fixes #506.
mapmeld/iD,bagage/iD,kartta-labs/iD,kepta/iD,digidem/iD,openstreetmap/iD,edpop/iD,energiekollektiv/openmod.sh-id,bagage/iD,edpop/iD,morray/iD,mapmeld/iD,energiekollektiv/openmod.sh-id,morray/iD,AndreasHae/iD,ngageoint/hootenanny-ui,bagage/iD,kepta/iD,openstreetmap/iD,tbicr/iD,andreic-telenav/iD,AndreasHae/iD,zbycz/iD,andreic-telenav/iD,AndreasHae/iD,1ec5/iD,1ec5/iD,kartta-labs/iD,openstreetmap/iD,tbicr/iD,edpop/iD,ngageoint/hootenanny-ui,digidem/iD,kartta-labs/iD,ngageoint/hootenanny-ui,1ec5/iD,zbycz/iD,mapmeld/iD