SIGABORT in dive site manager

[Sergey Starosek]

- Enter dive site manager UI by selecting dive with location
- Close current logbook (Ctrl-W)
- Press 'Apply changes' button in dive site manager

*** Error in `/home/star/src/subsurface/subsurface': double free or corruption (out): 0x0000000000dc7150 ***

Program received signal SIGABRT, Aborted.
0x00007ffff39a3cc9 in raise () from /lib/x86_64-linux-gnu/libc.so.6
(gdb) bt
#0  0x00007ffff39a3cc9 in raise () from /lib/x86_64-linux-gnu/libc.so.6
#1  0x00007ffff39a70d8 in abort () from /lib/x86_64-linux-gnu/libc.so.6
#2  0x00007ffff39e0f24 in ?? () from /lib/x86_64-linux-gnu/libc.so.6
#3  0x00007ffff39ed1fe in ?? () from /lib/x86_64-linux-gnu/libc.so.6
#4  0x00000000004e3520 in LocationInformationWidget::acceptChanges() ()
#5  0x00007ffff47ea2a6 in QMetaObject::activate(QObject*, int, int, void**) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#6  0x00007ffff58cba52 in QAction::triggered(bool) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#7  0x00007ffff58cdf38 in QAction::activate(QAction::ActionEvent) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#8  0x00007ffff59c9bed in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#9  0x00007ffff59c9d24 in QAbstractButton::mouseReleaseEvent(QMouseEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5

Sergey