KeywordMute matcher: more closely mimic Regexp#=~ behavior.

Regexp#=~ returns nil if it does not match.  An empty mute set does not
match any status, so KeywordMute::Matcher#=~ ought to return nil also.

1 files changed, 1 insertions, 1 deletions

diff --git a/app/models/glitch/keyword_mute.rb b/app/models/glitch/keyword_mute.rb
index 20fd89d9b..a7ab3650e 100644
--- a/app/models/glitch/keyword_mute.rb
+++ b/app/models/glitch/keyword_mute.rb
@@ -61,7 +61,7 @@ class Glitch::KeywordMute < ApplicationRecord
     end
 
     def =~(str)
-      regex ? regex =~ str : false
+      regex ? regex =~ str : nil
     end
   end
 end