Don't populate the password field on signup validation errors.
Don't populate the password field on signup validation errors.

- Previously, we were pulling `params[:user][:password] as the default
  value for the password field. This is incorrect; we should be pulling
  it from `@user.password` or the like.

shinexiao/gitlabhq,stoplightio/gitlabhq,mr-dxdy/gitlabhq,t-zuehlsdorff/gitlabhq,Soullivaneuh/gitlabhq,mmkassem/gitlabhq,allysonbarros/gitlabhq,openwide-java/gitlabhq,htve/GitlabForChinese,stoplightio/gitlabhq,dwrensha/gitlabhq,larryli/gitlabhq,t-zuehlsdorff/gitlabhq,t-zuehlsdorff/gitlabhq,mmkassem/gitlabhq,shinexiao/gitlabhq,jirutka/gitlabhq,allysonbarros/gitlabhq,axilleas/gitlabhq,LUMC/gitlabhq,stoplightio/gitlabhq,iiet/iiet-git,dplarson/gitlabhq,LUMC/gitlabhq,dreampet/gitlab,larryli/gitlabhq,Soullivaneuh/gitlabhq,dwrensha/gitlabhq,Soullivaneuh/gitlabhq,darkrasid/gitlabhq,daiyu/gitlab-zh,Soullivaneuh/gitlabhq,htve/GitlabForChinese,larryli/gitlabhq,axilleas/gitlabhq,darkrasid/gitlabhq,icedwater/gitlabhq,icedwater/gitlabhq,dreampet/gitlab,htve/GitlabForChinese,dreampet/gitlab,shinexiao/gitlabhq,dplarson/gitlabhq,SVArago/gitlabhq,htve/GitlabForChinese,LUMC/gitlabhq,larryli/gitlabhq,openwide-java/gitlabhq,mr-dxdy/gitlabhq,SVArago/gitlabhq,openwide-java/gitlabhq,dwrensha/gitlabhq,screenpages/gitlabhq,jirutka/gitlabhq,daiyu/gitlab-zh,darkrasid/gitlabhq,dplarson/gitlabhq,stoplightio/gitlabhq,iiet/iiet-git,allysonbarros/gitlabhq,screenpages/gitlabhq,dplarson/gitlabhq,dwrensha/gitlabhq,martijnvermaat/gitlabhq,screenpages/gitlabhq,axilleas/gitlabhq,icedwater/gitlabhq,martijnvermaat/gitlabhq,mmkassem/gitlabhq,SVArago/gitlabhq,LUMC/gitlabhq,SVArago/gitlabhq,mr-dxdy/gitlabhq,dreampet/gitlab,mmkassem/gitlabhq,martijnvermaat/gitlabhq,iiet/iiet-git,allysonbarros/gitlabhq,martijnvermaat/gitlabhq,iiet/iiet-git,daiyu/gitlab-zh,openwide-java/gitlabhq,screenpages/gitlabhq,jirutka/gitlabhq,axilleas/gitlabhq,jirutka/gitlabhq,daiyu/gitlab-zh,t-zuehlsdorff/gitlabhq,shinexiao/gitlabhq,darkrasid/gitlabhq,icedwater/gitlabhq,mr-dxdy/gitlabhq