MacOS package script: do not fail if link to /Applications already exists.
MacOS package script: do not fail if link to /Applications already exists.

ejgallego/coq,silene/coq,maximedenes/coq,silene/coq,mattam82/coq,amintimany/coq,coq/coq,ppedrot/coq,letouzey/coq-wip,ppedrot/coq,herbelin/github-coq,Lionel-Rieg/coq,JasonGross/coq,Zimmi48/coq,maximedenes/coq,ppedrot/coq,gares/coq,letouzey/coq-wip,letouzey/coq-wip,amintimany/coq,ejgallego/coq,SkySkimmer/coq,herbelin/github-coq,letouzey/coq-wip,Zimmi48/coq,coq/coq,gares/coq,SkySkimmer/coq,Lionel-Rieg/coq,william-lawvere/coq,coq/coq,gares/coq,mattam82/coq,JasonGross/coq,Matafou/coq,Matafou/coq,Ptival/coq,ppedrot/coq,ppedrot/coq,Zimmi48/coq,Zimmi48/coq,gares/coq,ejgallego/coq,william-lawvere/coq,SkySkimmer/coq,silene/coq,gares/coq,ejgallego/coq,Ptival/coq,amintimany/coq,herbelin/github-coq,letouzey/coq-wip,JasonGross/coq,Lionel-Rieg/coq,Matafou/coq,maximedenes/coq,Ptival/coq,mattam82/coq,coq/coq,JasonGross/coq,maximedenes/coq,SkySkimmer/coq,maximedenes/coq,william-lawvere/coq