test: fix test for non-OSX

The block is indented, and the comment mentions it's for OSX. Without this, on both Windows and a Linux VM I get the error (except for path, which obviously varies):

```
ERROR: WGL: OpenGL profile requested but WGL_ARB_create_context_profile is unavailable
 in error at error.jl:21
while loading C:\Users\patrick\.julia\v0.3\ModernGL\test\runtests.jl, in expression starting on line 157
```

This fixes the Windows case, and I suspect also the Linux case but I haven't verified.