On on EMF+ images generated by ChemDraw, some elements were not displayed.
After investigation, occurs that position of points was not read
properly in same cases. This commit fixes such cases.

Change-Id: I1d01d8defc41f4e437a669ef1268b8e33823cfc1
Reviewed-on: https://gerrit.libreoffice.org/37406Reviewed-by: Bartosz Kosiorek <gang65@poczta.onet.pl>
Tested-by: Bartosz Kosiorek <gang65@poczta.onet.pl>