Merge branch 'gmm5.2-compat' into 'master'

Fix compile error with GMM++-5.2, cf. #3

See merge request !25
5 jobs for master in 7 minutes and 14 seconds
Status Job ID Name Coverage
  Test
passed #38603
Qt551 VS2013
CoMISo-VS2013-Qt-5.5.1-x64

00:01:14

passed #38601
Linux
clang-c++11

00:06:57

passed #38600
Linux
gcc-c++11

00:07:12

passed #38602
Apple
macos-c++11

00:02:31

 
  Deploy
passed #38604
trigger_build

00:00:01