modified the add_face function of importerT to always return a valid

FaceHandle
23 jobs for 45-possible-importer-bug in 62 minutes and 21 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Test
passed #31180
VS2013
VS2013-32-bit-shared-apps

00:05:06

passed #31181
VS2013
VS2013-32-bit-shared-no-apps

00:03:35

passed #31184
VS2013
VS2013-32-bit-static-apps

00:04:36

passed #31185
VS2013
VS2013-32-bit-static-no-apps

00:03:57

passed #31178
VS2013
VS2013-64-bit-shared-apps

00:05:05

passed #31179
VS2013
VS2013-64-bit-shared-no-apps

00:04:08

passed #31182
VS2013
VS2013-64-bit-static-apps

00:05:09

passed #31183
VS2013
VS2013-64-bit-static-no-apps

00:04:18

passed #31172
VS2015
VS2015-32-bit-shared-apps

00:06:16

passed #31173
VS2015
VS2015-32-bit-shared-no-apps

00:04:59

passed #31176
VS2015
VS2015-32-bit-static-apps

00:06:03

passed #31177
VS2015
VS2015-32-bit-static-no-apps

00:05:07

passed #31170
VS2015
VS2015-64-bit-shared-apps

00:07:02

passed #31171
VS2015
VS2015-64-bit-shared-no-apps

00:05:33

passed #31174
VS2015
VS2015-64-bit-static-apps

00:06:57

passed #31175
VS2015
VS2015-64-bit-static-no-apps

00:05:43

passed #31164
Linux
clang-c++11

00:28:08

passed #31166
Linux
clang-c++14

00:30:21

passed #31169
Linux
cppcheck

00:01:05

passed #31163
Linux
gcc-c++11

00:05:10

passed #31165
Linux
gcc-c++14

00:06:22

passed #31167
Apple
macos-c++11

00:09:40

passed #31168
Apple
macos-c++98

00:09:43