Corrects the erroneous error message when trying to unfocus a fully unfocused proof (part of bug #2671).
Corrects the erroneous error message when trying to unfocus a fully
unfocused proof (part of bug #2671).

git-svn-id: 44dc50bdcc0f5d1a212c497508dc9452e0b35e2b@15011 85f007b7-540e-0410-9357-904b9bb8a0f7

barras/coq,maximedenes/coq,mlasson/coq,jpdeplaix/coq,gares/coq,asr/coq,pirbo/coq,8l/coq,TheTypoMaster/coq,SkySkimmer/coq,asr/coq,TOSPIO/coq,pirapira/coq2rust,shindere/coq,ale-f/coq,mattam82/coq,barras/coq,Zimmi48/coq,TheTypoMaster/coq,ejgallego/coq,maximedenes/coq,TOSPIO/coq,gmalecha/coq,JasonGross/coq,ale-f/coq,Zimmi48/coq,pirapira/coq2rust,coq/coq,aspiwack/coq,Zimmi48/coq,herbelin/github-coq,letouzey/coq-wip,gmalecha/coq,gares/coq,amintimany/coq,william-lawvere/coq,jhjourdan/coq,gares/coq,coq/coq,TheTypoMaster/coq,8l/coq,shindere/coq,william-lawvere/coq,maximedenes/coq,SkySkimmer/coq,ale-f/coq,Lionel-Rieg/coq,mattam82/coq,JasonGross/coq,Ptival/coq,Matafou/coq,Lionel-Rieg/coq,asr/coq,pirbo/coq,maximedenes/coq,amintimany/coq,aspiwack/coq,gares/coq,jpdeplaix/coq,pirbo/coq,barras/coq,william-lawvere/coq,amintimany/coq,maximedenes/coq,ejgallego/coq,SkySkimmer/coq,ejgallego/coq,silene/coq,Ptival/coq,Zimmi48/coq,letouzey/coq-wip,silene/coq,aspiwack/coq,mattam82/coq,TOSPIO/coq,letouzey/coq-wip,silene/coq,JasonGross/coq,letouzey/coq-wip,ppedrot/coq,Matafou/coq,gmalecha/coq,jpdeplaix/coq,herbelin/github-coq,JasonGross/coq,shindere/coq,letouzey/coq-wip,ppedrot/coq,gares/coq,ejgallego/coq,Matafou/coq,SkySkimmer/coq,8l/coq,jhjourdan/coq,ppedrot/coq,pirapira/coq2rust,coq/coq,Ptival/coq,ppedrot/coq,herbelin/github-coq,coq/coq,ppedrot/coq,Lionel-Rieg/coq,mlasson/coq,jhjourdan/coq,mlasson/coq