Fix occasional everpad-provider segfaults

[SlavikZ]

Sometimes everpad-provider crash with segfault on start. There's always dbus.so library functions calls in the crash trace.

[nvbn]

Thank you!

[SlavikZ]

I was glad help to make everpad better!

[utkarshsins]

Thanks SlavikZ

Confirming fixes segfaults of following trace in get_keyring().get_password() : everpad/provider/tools.py -

Program received signal SIGSEGV, Segmentation fault.
0x00007ffff26ebd40 in ?? () from /lib/x86_64-linux-gnu/libdbus-1.so.3
(gdb) backtrace
#0  0x00007ffff26ebd40 in ?? () from /lib/x86_64-linux-gnu/libdbus-1.so.3
#1  0x00007ffff26ea9ad in ?? () from /lib/x86_64-linux-gnu/libdbus-1.so.3
#2  0x00007ffff26eaa19 in ?? () from /lib/x86_64-linux-gnu/libdbus-1.so.3
#3  0x00007ffff26e9ea7 in ?? () from /lib/x86_64-linux-gnu/libdbus-1.so.3
#4  0x00007ffff26ea675 in ?? () from /lib/x86_64-linux-gnu/libdbus-1.so.3
#5  0x00007ffff26d3539 in ?? () from /lib/x86_64-linux-gnu/libdbus-1.so.3
#6  0x00007ffff26d3f66 in dbus_connection_get_dispatch_status () from /lib/x86_64-linux-gnu/libdbus-1.so.3
#7  0x00007fffed19ecc3 in ?? () from /usr/lib/x86_64-linux-gnu/libdbus-glib-1.so.2
#8  0x00007ffff49f568d in g_main_context_prepare () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#9  0x00007ffff49f5f03 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#10 0x00007ffff49f60ec in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#11 0x00007ffff53797a1 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#12 0x00007ffff0a9dbb6 in ?? () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#13 0x00007ffff534b0af in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#14 0x00007ffff534b3a5 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#15 0x00007ffff5350b79 in QCoreApplication::exec() () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#16 0x00007ffff16ca56d in ?? () from /usr/lib/python2.7/dist-packages/PySide/QtGui.so
#17 0x000000000052d432 in PyEval_EvalFrameEx ()
#18 0x000000000052cf32 in PyEval_EvalFrameEx ()
#19 0x000000000055c594 in PyEval_EvalCodeEx ()
#20 0x00000000005b7392 in PyEval_EvalCode ()
#21 0x0000000000469663 in ?? ()
#22 0x00000000004699e3 in PyRun_FileExFlags ()
#23 0x0000000000469f1c in PyRun_SimpleFileExFlags ()
#24 0x000000000046ab81 in Py_Main ()
#25 0x00007ffff7817ec5 in __libc_start_main (main=0x46ac3f <main>, argc=2, argv=0x7fffffffe568, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fffffffe558) at libc-start.c:287
#26 0x000000000057497e in _start ()

[nvbn]

Thank you.