Eliminate warnings

I saw warnings.

/Users/trsw/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/icalendar-2.1.1/lib/icalendar/values/text.rb:19: warning: ambiguous first argument; put parentheses or even spaces
/Users/trsw/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/icalendar-2.1.1/lib/icalendar/values/utc_offset.rb:33: warning: ambiguous first argument; put parentheses or even spaces

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My environment.
MacOSX 10.9.4
ruby --version
ruby 2.1.2p95 (2014-05-08 revision 45877) [x86_64-darwin13.0]