also update logo in user documentation sources

8 jobs for logo-update
Status Name Job ID Coverage
  Test
passed clang-c++11-Qt4 #4350
Linux MultiThreads

00:07:37

passed clang-c++11-Qt5 #4354
Linux MultiThreads

00:09:57

passed clang-c++98-Qt4 #4352
Linux MultiThreads

00:06:33

passed clang-c++98-Qt5 #4356
Linux MultiThreads

00:07:18

passed gcc-c++11-Qt4 #4349
Linux

01:07:46

passed gcc-c++11-Qt5 #4353
Linux

00:03:33

passed gcc-c++98-Qt4 #4351
Linux

00:02:54

passed gcc-c++98-Qt5 #4355
Linux

00:03:03