Fix typo (remove additional ".freeze")

Author: jcoyne

lib/rdf/model/uri.rb

@@ -57,7 +57,7 @@ class URI
 
     IQUERY = Regexp.compile("(?:#{IPCHAR}|#{IPRIVATE}|/|\\?)*").freeze
 
-    IFRAGMENT = Regexp.compile("(?:#{IPCHAR}|/|\\?)*").freeze.freeze
+    IFRAGMENT = Regexp.compile("(?:#{IPCHAR}|/|\\?)*").freeze
 
     ISEGMENT = Regexp.compile("(?:#{IPCHAR})*").freeze
     ISEGMENT_NZ = Regexp.compile("(?:#{IPCHAR})+").freeze