refman: fix broken urls
refman: fix broken urls

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