Fix wrong whitespaces in url tags

• https://edugit.org/AlekSIS/official/AlekSIS-App-Alsijil/-/blob/master/aleksis/apps/alsijil/templates/alsijil/class_register/lesson.html#L28
• https://edugit.org/AlekSIS/official/AlekSIS-App-Alsijil/-/blob/master/aleksis/apps/alsijil/templates/alsijil/class_register/lesson.html#L37

Broken by @ZugBahnHof

added part::frontend prio::1 type::bug workflow::confirmed labels

assigned to @hansegucker

created merge request !211 (merged) to address this issue

mentioned in merge request !211 (merged)

marked the checklist item https://edugit.org/AlekSIS/official/AlekSIS-App-Alsijil/-/blob/master/aleksis/apps/alsijil/templates/alsijil/class_register/lesson.html#L37 as completed

marked the checklist item https://edugit.org/AlekSIS/official/AlekSIS-App-Alsijil/-/blob/master/aleksis/apps/alsijil/templates/alsijil/class_register/lesson.html#L28 as completed

closed with commit 69f872a3

mentioned in commit 69f872a3