Update OpenFlipper.cc

Added width specifier to format.
7 jobs for fixStereo in 49 minutes and 55 seconds (queued for 1 second)
Status Name Job ID Coverage
  Test
passed clang-c++11-Qt5 #18041
Linux MultiThreads

00:08:29

passed cppcheck #18042
Linux MultiThreads

00:37:58

passed gcc-c++11-Qt5 #18040
Linux

00:04:02

passed Mac-Cpp11 #18046
Apple

00:49:53

passed VS2013-Qt-5.5.1-x64 #18045
VS2013 Qt551

00:15:07

passed VS2015-Qt-5.6.0-x32 #18044
Qt56 VS2015

00:19:51

passed VS2015-Qt-5.6.0-x64 #18043
VS2015 Qt56

00:17:25