make youtube regex case insensitive (#1710)
make youtube regex case insensitive (#1710)


switch-education/pxt,switch-education/pxt,Microsoft/pxt,switch-education/pxt,Microsoft/pxt,Microsoft/pxt,switch-education/pxt,switchinnovations/pxt,switchinnovations/pxt,playi/pxt,playi/pxt,Microsoft/pxt,playi/pxt,playi/pxt,Microsoft/pxt,switchinnovations/pxt,switchinnovations/pxt,switch-education/pxt