bineditor: don't crash when no error string is requested
bineditor: don't crash when no error string is requested

Task-number: QTCREATORBUG-7930
Change-Id: Ia3b2a21d843ce9de7f61f754da0b276355c377f2
Reviewed-by: Christian Kandeler <3aa99dcdd3f0cac61fb81c2a11771c0cc2497607@digia.com>

syntheticpp/qt-creator,darksylinc/qt-creator,farseerri/git_code,amyvmiwei/qt-creator,richardmg/qtcreator,xianian/qt-creator,farseerri/git_code,xianian/qt-creator,syntheticpp/qt-creator,martyone/sailfish-qtcreator,amyvmiwei/qt-creator,darksylinc/qt-creator,farseerri/git_code,martyone/sailfish-qtcreator,amyvmiwei/qt-creator,AltarBeastiful/qt-creator,malikcjm/qtcreator,xianian/qt-creator,darksylinc/qt-creator,AltarBeastiful/qt-creator,danimo/qt-creator,kuba1/qtcreator,colede/qtcreator,omniacreator/qtcreator,Distrotech/qtcreator,kuba1/qtcreator,amyvmiwei/qt-creator,maui-packages/qt-creator,xianian/qt-creator,martyone/sailfish-qtcreator,darksylinc/qt-creator,kuba1/qtcreator,darksylinc/qt-creator,duythanhphan/qt-creator,richardmg/qtcreator,amyvmiwei/qt-creator,duythanhphan/qt-creator,syntheticpp/qt-creator,colede/qtcreator,syntheticpp/qt-creator,danimo/qt-creator,omniacreator/qtcreator,kuba1/qtcreator,martyone/sailfish-qtcreator,malikcjm/qtcreator,Distrotech/qtcreator,syntheticpp/qt-creator,martyone/sailfish-qtcreator,danimo/qt-creator,AltarBeastiful/qt-creator,duythanhphan/qt-creator,xianian/qt-creator,xianian/qt-creator,colede/qtcreator,darksylinc/qt-creator,kuba1/qtcreator,richardmg/qtcreator,duythanhphan/qt-creator,colede/qtcreator,malikcjm/qtcreator,amyvmiwei/qt-creator,richardmg/qtcreator,danimo/qt-creator,xianian/qt-creator,AltarBeastiful/qt-creator,colede/qtcreator,AltarBeastiful/qt-creator,martyone/sailfish-qtcreator,syntheticpp/qt-creator,danimo/qt-creator,xianian/qt-creator,martyone/sailfish-qtcreator,kuba1/qtcreator,richardmg/qtcreator,richardmg/qtcreator,maui-packages/qt-creator,danimo/qt-creator,malikcjm/qtcreator,omniacreator/qtcreator,duythanhphan/qt-creator,kuba1/qtcreator,maui-packages/qt-creator,farseerri/git_code,colede/qtcreator,farseerri/git_code,AltarBeastiful/qt-creator,amyvmiwei/qt-creator,maui-packages/qt-creator,maui-packages/qt-creator,richardmg/qtcreator,farseerri/git_code,Distrotech/qtcreator,omniacreator/qtcreator,martyone/sailfish-qtcreator,maui-packages/qt-creator,omniacreator/qtcreator,danimo/qt-creator,colede/qtcreator,danimo/qt-creator,syntheticpp/qt-creator,Distrotech/qtcreator,Distrotech/qtcreator,malikcjm/qtcreator,xianian/qt-creator,AltarBeastiful/qt-creator,duythanhphan/qt-creator,maui-packages/qt-creator,darksylinc/qt-creator,omniacreator/qtcreator,farseerri/git_code,malikcjm/qtcreator,Distrotech/qtcreator,duythanhphan/qt-creator,amyvmiwei/qt-creator,omniacreator/qtcreator,malikcjm/qtcreator,farseerri/git_code,darksylinc/qt-creator,martyone/sailfish-qtcreator,kuba1/qtcreator,danimo/qt-creator,Distrotech/qtcreator,AltarBeastiful/qt-creator,kuba1/qtcreator