Fix segfault that occurs when running commands from GUI

Earlier today, BMTF found that the BMTF SWATCH cell at Point 5 crashed when a command was run from the web GUI (specifically the MP7 'scan SD card' command). Stack trace from core dump:

#0  swatchcellframework::CommandPanel::getCommandStatus (this=0x7f08182fabb0, cgi=..., out=...) at /usr/src/debug/cactuscore-swatchcellframework-1.4.1/src/common/CommandPanel.cpp:395
#1  0x00007f081fc4f1b0 in ajax::EventHandler::Callback<swatchcellframework::CommandPanel>::invoke (this=0x7f08182cfb20, cgi=..., out=...) at /opt/xdaq/include/ajax/EventHandler.h:132
#2  0x00007f082daf65b9 in ajax::EventHandler::callHandler(cgicc::Cgicc&, std::ostream&) () at /usr/src/debug/cmsos-cactuscore-tsajaxell-5.2.0/src/common/EventHandler.cc:110
#3  0x00007f082daf2a9f in ajax::AutoHandledWidget::callHandler(cgicc::Cgicc&, std::ostream&) [clone .localalias.13] () at /usr/src/debug/cmsos-cactuscore-tsajaxell-5.2.0/src/common/AutoHandledWidget.cc:62
#4  0x00007f082daf04b1 in ajax::AutoHandledWidget::callHandler (this=0x7f08182ce280, cgi=..., out=...) at /usr/src/debug/cmsos-cactuscore-tsajaxell-5.2.0/src/common/AutoHandledWidget.cc:77
#5  0x00007f082dd65d3c in tsframework::CellAbstract::Default(xgi::Input*, xgi::Output*) () at /usr/src/debug/cmsos-cactuscore-tsframework-5.2.1/src/common/CellAbstract.cc:448
#6  0x00007f08729284ae in executive::XgiDispatcher::processIncomingMessage(xgi::Input*, xgi::Output*) () at /usr/src/debug/cmsos-core-executive-4.1.0/src/common/XgiDispatcher.cc:231
#7  0x00007f08721d787e in pt::http::ReceiverLoop::onRequest(std::string const&, std::string const&) () at /usr/src/debug/cmsos-core-pthttp-4.6.0/src/common/ReceiverLoop.cc:1536
#8  0x00007f08721db94f in pt::http::ReceiverLoop::process(toolbox::task::WorkLoop*) () at /usr/src/debug/cmsos-core-pthttp-4.6.0/src/common/ReceiverLoop.cc:668
#9  0x00007f0881dc105a in toolbox::task::WaitingWorkLoop::process (this=0x5fc5740) at /usr/src/debug/cmsos-core-toolbox-9.13.0/src/common/task/WaitingWorkLoop.cc:43
#10 0x00007f0881dbc911 in toolbox::task::WorkLoop::run (this=this@entry=0x5fc5740) at /usr/src/debug/cmsos-core-toolbox-9.13.0/src/common/task/WorkLoop.cc:209
#11 0x00007f0881dbce67 in toolbox::task::thread_func (workLoop=0x5fc5740) at /usr/src/debug/cmsos-core-toolbox-9.13.0/src/common/task/WorkLoop.cc:79
#12 0x00007f0882874dd5 in start_thread () from /lib64/libpthread.so.0
#13 0x00007f087f516ead in clone () from /lib64/libc.so.6

SWATCH version: 1.4.1

This merge request should resolve that bug.