Fixed GFM autocomplete regex
Fixed GFM autocomplete regex

Without this fix it is possible that the autocomplete popup will stay open with the very first match, no matter if there is a match further in the string.

Closes #25119

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