Add a safeguard in User#set_projects_limit
Add a safeguard in User#set_projects_limit

Signed-off-by: Rémy Coutable <4ea0184b9df19e0786dd00b28e6daa4d26baeb3e@rymai.me>

dplarson/gitlabhq,screenpages/gitlabhq,shinexiao/gitlabhq,jirutka/gitlabhq,dplarson/gitlabhq,iiet/iiet-git,htve/GitlabForChinese,dreampet/gitlab,screenpages/gitlabhq,t-zuehlsdorff/gitlabhq,screenpages/gitlabhq,iiet/iiet-git,stoplightio/gitlabhq,stoplightio/gitlabhq,openwide-java/gitlabhq,htve/GitlabForChinese,mmkassem/gitlabhq,dreampet/gitlab,dplarson/gitlabhq,axilleas/gitlabhq,jirutka/gitlabhq,LUMC/gitlabhq,openwide-java/gitlabhq,daiyu/gitlab-zh,openwide-java/gitlabhq,stoplightio/gitlabhq,darkrasid/gitlabhq,shinexiao/gitlabhq,jirutka/gitlabhq,darkrasid/gitlabhq,dplarson/gitlabhq,darkrasid/gitlabhq,axilleas/gitlabhq,shinexiao/gitlabhq,screenpages/gitlabhq,LUMC/gitlabhq,LUMC/gitlabhq,dreampet/gitlab,axilleas/gitlabhq,t-zuehlsdorff/gitlabhq,daiyu/gitlab-zh,mmkassem/gitlabhq,mmkassem/gitlabhq,t-zuehlsdorff/gitlabhq,iiet/iiet-git,jirutka/gitlabhq,LUMC/gitlabhq,axilleas/gitlabhq,htve/GitlabForChinese,openwide-java/gitlabhq,t-zuehlsdorff/gitlabhq,darkrasid/gitlabhq,stoplightio/gitlabhq,daiyu/gitlab-zh,daiyu/gitlab-zh,htve/GitlabForChinese,dreampet/gitlab,iiet/iiet-git,mmkassem/gitlabhq,shinexiao/gitlabhq