`site()` input param destructed not properly, fixed

Got this error while make'ing the project:

[··· ~/Documents/erlang-patterns/erlang-patterns ↵]
make
rm -f site/*.html
lpad-gen
=== ERROR ===
{{required_value,patterns},
 [{plist,value,2,[{file,"src/plist.erl"},{line,27}]},
  {index,site,1,
         [{file,"/Users/zarkone/Documents/erlang-patterns/erlang-patterns/index.erl"},
          {line,18}]},
  {lpad,generator_specs,2,[{file,"src/lpad.erl"},{line,191}]},
  {lpad,process_index,2,[{file,"src/lpad.erl"},{line,103}]},
  {lpad,run,2,[{file,"src/lpad.erl"},{line,37}]},
  {erl_eval,local_func,5,[{file,"erl_eval.erl"},{line,556}]},
  {erl_eval,expr_list,6,[{file,"erl_eval.erl"},{line,877}]},
  {erl_eval,local_func,5,[{file,"erl_eval.erl"},{line,551}]}]}

make: *** [gen] Error 1

gar1t / erlang-patterns

`site()` input param destructed not properly, fixed #28