Fix Version metadata have trailing dot (#2403)

lib/mastodon/version.rb

@@ -25,7 +25,7 @@ module Mastodon
     end
 
     def build_metadata
-      ['glitch', ENV.fetch('MASTODON_VERSION_METADATA', nil)].compact.join('.')
+      ['glitch', ENV.fetch('MASTODON_VERSION_METADATA', nil)].compact_blank.join('.')
     end
 
     def to_a