fix(\n): Fix first occurrence of \n line ending

Previously the first occurrence of a '\n' or '\r' character would be removed if
the file did not start with \r\n.

Fixes [Issue #9](https://github.com/pc035860/angular-highlightjs/issues/9). This turned out to be a bug after all. I was onable to reproduce it on plunkr, because the loaded template contains \r\n line endings.