Update IRC links to libera

In README, in OpenCS about dialog, in Travis notification

.travis.yml

@@ -74,7 +74,7 @@ notifications:
   irc:
     if: repository_slug = OpenMW/openmw AND branch = master
     channels:
-      - "chat.freenode.net#openmw"
+      - "irc.libera.chat#openmw"
     on_success: change
     on_failure: always
     use_notice: true

README.md

@@ -10,7 +10,7 @@ OpenMW also comes with OpenMW-CS, a replacement for Bethesda's Construction Set.
 * Version: 0.47.0
 * License: GPLv3 (see [LICENSE](https://github.com/OpenMW/openmw/blob/master/LICENSE) for more information)
 * Website: https://www.openmw.org
-* IRC: #openmw on irc.freenode.net
+* IRC: #openmw on irc.libera.chat
 
 Font Licenses:
 * DejaVuLGCSansMono.ttf: custom (see [files/mygui/DejaVuFontLicense.txt](https://github.com/OpenMW/openmw/blob/master/files/mygui/DejaVuFontLicense.txt) for more information)

apps/opencs/view/doc/view.cpp

@@ -749,7 +749,7 @@ void CSVDoc::View::infoAbout()
     "<tr><td>%4</td><td><a href=\"https://openmw.org\">https://openmw.org</a></td></tr>"
     "<tr><td>%5</td><td><a href=\"https://forum.openmw.org\">https://forum.openmw.org</a></td></tr>"
     "<tr><td>%6</td><td><a href=\"https://gitlab.com/OpenMW/openmw/issues\">https://gitlab.com/OpenMW/openmw/issues</a></td></tr>"
-    "<tr><td>%7</td><td><a href=\"https://webchat.freenode.net/?channels=openmw&uio=OT10cnVlde\">irc://irc.freenode.net/#openmw</a></td></tr>"
+    "<tr><td>%7</td><td><a href=\"https://web.libera.chat/#openmw\">ircs://irc.libera.chat/#openmw</a></td></tr>"
     "</table>"
     "</p>")
     .arg(versionInfo