Module tls potentially included by two different applications: ejabberd and ssl.

This rename is to avoid the following error when running `make rel`

```
{'EXIT',{{badmatch,{error,"Module tls potentially included by two different applications: ejabberd and ssl."}},
         [{rebar_reltool,generate,2,
                         [{file,"src/rebar_reltool.erl"},{line,50}]},
          {rebar_core,run_modules,4,[{file,"src/rebar_core.erl"},{line,404}]},
          {rebar_core,execute,5,[{file,"src/rebar_core.erl"},{line,333}]},
          {rebar_core,process_dir0,6,[{file,"src/rebar_core.erl"},{line,195}]},
          {rebar_core,process_each,5,[{file,"src/rebar_core.erl"},{line,266}]},
          {rebar_core,process_dir0,6,[{file,"src/rebar_core.erl"},{line,171}]},
          {rebar_core,process_commands,2,
                      [{file,"src/rebar_core.erl"},{line,60}]},
          {rebar,main,1,[{file,"src/rebar.erl"},{line,56}]}]}}
```

I do not know if this is the correct thing to do. I also am not that familiar with reltool so I do not know if I can just fix this by changing the configuration. Just wanted to post this to create the issue etc.

Thanks!