Dockerfile: update go-swagger to fix validation on Go1.16
Dockerfile: update go-swagger to fix validation on Go1.16

Signed-off-by: Sebastiaan van Stijn <64b2b6d12bfe4baae7dad3d018f8cbf6b0e7a044@gone.nl>

yosifkit/docker,AkihiroSuda/docker,Mokolea/docker,bearstech/moby,AkihiroSuda/docker,vdemeester/docker,docker/docker,cpuguy83/docker,nalind/docker,nawawi/docker,konstruktoid/docker-upstream,moby/moby,thaJeztah/docker,thaJeztah/docker,jimjag/docker,trebonian/docker,AkihiroSuda/docker,Ramzec/docker,trebonian/docker,cpuguy83/docker,mahak/docker,jthelin/docker,jimjag/docker,moul/docker,jimjag/docker,gnailuy/docker,paralin/docker,paralin/docker,bearstech/moby,moul/docker,djs55/docker,nawawi/docker,thaJeztah/docker,vdemeester/docker,moby/moby,bearstech/moby,cpuguy83/docker,yosifkit/docker,moul/docker,djs55/docker,jthelin/docker,paralin/docker,gnailuy/docker,trebonian/docker,nalind/docker,konstruktoid/docker-upstream,gnailuy/docker,konstruktoid/docker-upstream,mahak/docker,Mokolea/docker,nawawi/docker,nalind/docker,djs55/docker,mahak/docker,moby/moby,Mokolea/docker,docker/docker,gnailuy/docker,trebonian/docker,AkihiroSuda/docker,flavio/docker,nalind/docker,jimjag/docker,paralin/docker,Mokolea/docker,mahak/docker,thaJeztah/docker,flavio/docker,bearstech/moby,yosifkit/docker,cpuguy83/docker,konstruktoid/docker-upstream,Ramzec/docker,jameszhan/docker,jameszhan/docker,yosifkit/docker,moul/docker,Ramzec/docker,vdemeester/docker,flavio/docker,Ramzec/docker,flavio/docker,jameszhan/docker,nawawi/docker,docker/docker,moby/moby