Fix incorrect dash in startup message (#1206)

Co-authored-by: tompng <tomoyapenguin@gmail.com>

Author: st0012

lib/irb/startup_message.rb

@@ -48,7 +48,7 @@ def load_logo
       end
 
       def build_info_lines
-        version_line = "#{Color.colorize('IRB', [:BOLD])} v#{VERSION} \u2014 Ruby #{RUBY_VERSION}"
+        version_line = "#{Color.colorize('IRB', [:BOLD])} v#{VERSION} - Ruby #{RUBY_VERSION}"
         tip_line = colorize_tip(TIPS.sample)
         dir_line = Color.colorize(short_pwd, [:CYAN])