Remove additional whitespaces in url tags in lesson.html

(cherry picked from commit fccd6d36)

CHANGELOG.rst

@@ -6,6 +6,14 @@ All notable changes to this project will be documented in this file.
 The format is based on `Keep a Changelog`_,
 and this project adheres to `Semantic Versioning`_.
 
+Unreleased
+----------
+
+Fixed
+~~~~~
+
+* Lesson view didn't work due to additional whitespaces in ``url`` tags.
+
 `2.0rc2`_ - 2021-06-26
 ----------------------
 

aleksis/apps/alsijil/templates/alsijil/class_register/lesson.html

@@ -25,7 +25,7 @@
           {# Next lesson #}
           {% if prev_lesson_person %}
             <a class="btn primary waves-effect waves-light alsijil-top-button"
-               href="{% url " lesson_period" prev_lesson_person.week.year prev_lesson_person.week.week prev_lesson_person.id %}">
+               href="{% url "lesson_period" prev_lesson_person.week.year prev_lesson_person.week.week prev_lesson_person.id %}">
             <i class="material-icons left">arrow_back</i>
             {% trans "My previous lesson" %}
             </a>
@@ -34,7 +34,7 @@
           {# Previous lesson #}
           {% if next_lesson_person %}
             <a class="btn primary right waves-effect waves-light alsijil-top-button"
-               href="{% url " lesson_period" next_lesson_person.week.year next_lesson_person.week.week next_lesson_person.id %}">
+               href="{% url "lesson_period" next_lesson_person.week.year next_lesson_person.week.week next_lesson_person.id %}">
             <i class="material-icons right">arrow_forward</i>
             {% trans "My next lesson" %}
             </a>