DEV: Bump logster version to 2.6.1 and enable new logster feature

Logster 2.6.1 includes a few new features and fixes. More details here: 58bb5c5368/CHANGELOG.md

Gemfile.lock

@@ -171,7 +171,7 @@ GEM
     logstash-event (1.2.02)
     logstash-logger (0.26.1)
       logstash-event (~> 1.2)
-    logster (2.5.1)
+    logster (2.6.1)
     loofah (2.4.0)
       crass (~> 1.0.2)
       nokogiri (>= 1.5.9)

config/initializers/100-logster.rb

@@ -150,3 +150,15 @@ if Rails.configuration.multisite
     chained && chained.first.formatter = RailsMultisite::Formatter.new
   end
 end
+
+Logster.config.project_directories = [
+  { path: Rails.root.to_s, url: "https://github.com/discourse/discourse", main_app: true }
+]
+Discourse.plugins.each do |plugin|
+  next if !plugin.metadata.url
+
+  Logster.config.project_directories << {
+    path: "#{Rails.root.to_s}/plugins/#{plugin.directory_name}",
+    url: plugin.metadata.url
+  }
+end