drop quotes in `eval "$(weave env)"`
drop quotes in `eval "$(weave env)"`

They are unnecessary and unwieldy.

Fixes #1596

paulbellamy/weave,awh/weave,dpw/weave,paulbellamy/weave,dpw/weave,weaveworks/weave,paulbellamy/weave,awh/weave,tomwilkie/weave,rade/weave,n054/weave,aaam/weave,n054/weave,dpw/weave,n054/weave,n054/weave,aaam/weave,dpw/weave,tomwilkie/weave,paulbellamy/weave,awh/weave,bboreham/weave,rade/weave,awh/weave,dpw/weave,aaam/weave,weaveworks/weave,rade/weave,rade/weave,bboreham/weave,bboreham/weave,bboreham/weave,tomwilkie/weave,rade/weave,tomwilkie/weave,weaveworks/weave,bboreham/weave,awh/weave,aaam/weave,tomwilkie/weave,weaveworks/weave,aaam/weave,n054/weave