fix for mplotqueries to not fail if the last line is empty.
fix for mplotqueries to not fail if the last line is empty.

ces0712/mtools,aerrami/mtools,aerrami/mtools,gormanb/mtools,ces0712/mtools,devkev/mtools,parkhyeonghwa/mtools,parkhyeonghwa/mtools,yaowenqiang/mtools,rueckstiess/mtools,tomzhang/mtools,devkev/mtools,corymintz/mtools,tomzhang/mtools,corymintz/mtools,tomzhang/mtools,rueckstiess/mtools,devkev/mtools,corymintz/mtools,yaowenqiang/mtools,gormanb/mtools,aerrami/mtools,parkhyeonghwa/mtools,yaowenqiang/mtools,gormanb/mtools,ces0712/mtools