Fix: READ() removing last character of file

[WhoBrokeTheBuild]

When a file does not end with a newline, READ() erroneously strips off the last character of the last line.
This simply checks that it is a newline before removing it.

example.txt

This line has a newline
This line doesn't

_file = fopen('example.txt', 'r')
read(_file) # "This line has a newline"
read(_file) # "This line doesn't"

Previously, the last read() would have returned "This line doesn'"