[autotests] tst_QLineEdit taskQTBUG_7395_readOnlyShortcut unstable

tst_QLineEdit taskQTBUG_7395_readOnlyShortcut is an unstable test on the CI infrastructure. It unstably fails when built by both QtBase and Qt5.

QT5
PASS - http://testresults.qt-project.org/ci/Qt5_master_Integration/build_00429/linux-g++_developer-build_qtnamespace_qtlibinfix_Ubuntu_11.10_x64/log.txt.gz
FAIL - http://testresults.qt-project.org/ci/Qt5_master_Integration/build_00430/linux-g++_developer-build_qtnamespace_qtlibinfix_Ubuntu_11.10_x64/log.txt.gz
FAIL - http://testresults.qt-project.org/ci/Qt5_master_Integration/build_00431/linux-g++_developer-build_qtnamespace_qtlibinfix_Ubuntu_11.10_x64/log.txt.gz
FAIL - http://testresults.qt-project.org/ci/Qt5_master_Integration/build_00432/linux-g++_developer-build_qtnamespace_qtlibinfix_Ubuntu_11.10_x64/log.txt.gz

QtBase
FAIL - http://testresults.qt-project.org/ci/QtBase_master_Integration/build_02060/linux-g++_developer-build_qtnamespace_qtlibinfix_Ubuntu_11.10_x64/log.txt.gz
PASS - http://testresults.qt-project.org/ci/QtBase_master_Integration/build_02061/linux-g++_developer-build_qtnamespace_qtlibinfix_Ubuntu_11.10_x64/log.txt.gz
PASS - http://testresults.qt-project.org/ci/QtBase_master_Integration/build_02062/linux-g++_developer-build_qtnamespace_qtlibinfix_Ubuntu_11.10_x64/log.txt.gz
PASS - http://testresults.qt-project.org/ci/QtBase_master_Integration/build_02063/linux-g++_developer-build_qtnamespace_qtlibinfix_Ubuntu_11.10_x64/log.txt.gz