Errors in element.rb

[patricklucas]

Running the first time with input from an nginx server, gltail crashed and I received the following traceback:

./bin/../lib/gl_tail/element.rb:280:in `glDeleteLists': no implicit conversion from nil to integer (TypeError)
    from ./bin/../lib/gl_tail/element.rb:280:in `render'
    from ./bin/../lib/gl_tail/block.rb:83:in `render'
    from ./bin/../lib/gl_tail/engine.rb:99:in `draw'
    from ./bin/../lib/gl_tail/engine.rb:97:in `each'
    from ./bin/../lib/gl_tail/engine.rb:97:in `draw'
    from ./bin/../lib/gl_tail/engine.rb:371:in `to_proc'
    from ./bin/../lib/gl_tail/engine.rb:353:in `call'
    from ./bin/../lib/gl_tail/engine.rb:353:in `glutMainLoop'
    from ./bin/../lib/gl_tail/engine.rb:353:in `start'
    from bin/gl_tail:111

I added to the if statement above it and @text_list to avoid the scenario, but I doubt that's the proper solution.

The same thing also occurred on line 255.

[petersondrew]

I actually did the same thing in my pull request here #20
I assumed it was happening due to a change moving from ruby_opengl to opengl, but it's probably just a bug regardless.