Update gitlab-shell version to 3.2.1 in the 8.9->8.10 update guide
Update gitlab-shell version to 3.2.1 in the 8.9->8.10 update guide

This was missing from gitlab-org/gitlab-ce!5509.

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

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