Optimized parsing output when creating only report.
Optimized parsing output when creating only report.

Update issue 1261
Optimized the code that omits keywords a little. Memory usage dropped ~5% and execution got a tiny bit faster. As a bonus the code is also a little cleaner.

userzimmermann/robotframework-python3,userzimmermann/robotframework-python3,userzimmermann/robotframework-python3,userzimmermann/robotframework-python3,userzimmermann/robotframework-python3