remove pipe character from allowed set for unqoted term

spec/query_lexer_spec.rb

@@ -129,15 +129,6 @@ class QueryLexerTester
       expect(@result[2][1]).to eq '"name with space"'
     end
 
-    it 'tests search term without quotes containing pipe characters' do
-      @result = @evaluator.tokenize('||')
-
-      expect(@result.length).to eq 1
-
-      expect(@result[0][0]).to eq :TERM_WITHOUT_QUOTES
-      expect(@result[0][1]).to eq '||'
-    end
-
     it 'tests search term with quotes containing non alphanumerical characters' do
       @result = @evaluator.tokenize('"|*|/\()#-!=<>&$"')