Fix all target="_blank" anchors to be safer

Fixes #1411

events/build_event.html

@@ -30,4 +30,4 @@
  for repository {{ event_data.repository | repository_reference }}
 {% if event_data.error_message %}
 <br>{{ event_data.error_message }}
-{% endif %}
+{% endif %}

events/build_failure.html

@@ -1,2 +1,2 @@
 {% extends "build_event.html" %}
-{% block eventkind %}failure{% endblock %}
+{% block eventkind %}failure{% endblock %}

events/build_queued.html

@@ -1,2 +1,2 @@
 {% extends "build_event.html" %}
-{% block eventkind %}queued{% endblock %}
+{% block eventkind %}queued{% endblock %}

events/build_start.html

@@ -1,2 +1,2 @@
 {% extends "build_event.html" %}
-{% block eventkind %}started{% endblock %}
+{% block eventkind %}started{% endblock %}

events/build_success.html

@@ -1,2 +1,2 @@
 {% extends "build_event.html" %}
-{% block eventkind %}completed{% endblock %}
+{% block eventkind %}completed{% endblock %}

events/vulnerability_found.html

@@ -1,4 +1,4 @@
 A <a href="{{ event_data.vulnerability.link }}">{{ event_data.vulnerability.priority }} vulnerability</a> ({{ event_data.vulnerability.id }}) was detected in tags
  {{ 'tags' | icon_image }}
 {% for tag in event_data.tags %}{%if loop.index > 1 %}, {% endif %}{{ (event_data.repository, tag) | repository_tag_reference }}{% endfor %} in
- repository {{ event_data.repository | repository_reference }}
+ repository {{ event_data.repository | repository_reference }}