Blank line filter in dataloader doesn't quite work

[adam-funk]

I assume line 44 in dataloader_iam.py is supposed to ignore blank lines as well as those starting with # but it doesn't work because lines read from the open file include the newline at the end. I think if not line or line[0] == '#' should be changed to if not line.strip() or line[0] == '#':.

[githubharald]

I think it was just intended to be used for comment lines, not for empty lines. But ignoring empty lines too makes sense, will add it.