Fix compilation failure on Linux with GCC 11.1

[acotty]

Fixes underlying issue as per issue 4.

[eranif]

this is strange, as I am constantly building it on Linux with no errors

eran@DESKTOP-F7URLL7:~/devl/dbgd/build-debug$ make -j$(nproc)
[  4%] Building CXX object dap/CMakeFiles/dapcxx.dir/ConnectionString.cpp.o
[ 12%] Building CXX object dap/CMakeFiles/dapcxx.dir/Client.cpp.o
[ 12%] Building CXX object dap/CMakeFiles/dapcxx.dir/DAPEvent.cpp.o
[ 16%] Building CXX object dap/CMakeFiles/dapcxx.dir/JSON.cpp.o
[ 25%] Building CXX object dap/CMakeFiles/dapcxx.dir/JsonRPC.cpp.o
[ 25%] Building CXX object dap/CMakeFiles/dapcxx.dir/Exception.cpp.o
[ 33%] Building CXX object dap/CMakeFiles/dapcxx.dir/Process.cpp.o
[ 33%] Building CXX object dap/CMakeFiles/dapcxx.dir/Log.cpp.o
[ 37%] Building CXX object dap/CMakeFiles/dapcxx.dir/ServerProtocol.cpp.o
[ 41%] Building CXX object dap/CMakeFiles/dapcxx.dir/SocketClient.cpp.o
[ 50%] Building CXX object dap/CMakeFiles/dapcxx.dir/StringUtils.cpp.o
[ 50%] Building CXX object dap/CMakeFiles/dapcxx.dir/Socket.cpp.o
[ 58%] Building CXX object dap/CMakeFiles/dapcxx.dir/cJSON.cpp.o
[ 58%] Building CXX object dap/CMakeFiles/dapcxx.dir/UnixProcess.cpp.o
[ 62%] Building CXX object dap/CMakeFiles/dapcxx.dir/dap.cpp.o
[ 70%] Building CXX object dap/CMakeFiles/dapcxx.dir/msw.cpp.o
[ 70%] Building CXX object dap/CMakeFiles/dapcxx.dir/linux.cpp.o
[ 75%] Building CXX object dap/CMakeFiles/dapcxx.dir/SocketServer.cpp.o
[ 79%] Linking CXX shared library libdapcxx.so
[ 79%] Built target dapcxx
[ 87%] Building CXX object dbgcli/CMakeFiles/dap_demo.dir/UI.cpp.o
[ 87%] Building CXX object dbgcli/CMakeFiles/dap_demo.dir/ConsoleApp.cpp.o
[ 91%] Building CXX object dbgcli/CMakeFiles/dap_demo.dir/MainFrame.cpp.o
[ 95%] Building CXX object dbgcli/CMakeFiles/dap_demo.dir/UI_dbgcli_bitmaps.cpp.o
[100%] Linking CXX executable dap_demo
[100%] Built target dap_demo

[eranif]

Also, this file wxStringHash.h is part of CodeLite sources (I wrote it to fix similar problems in CodeLite sources)
but note that it is not part of this project (i.e. it does not exist in this repository) - so merging this PR will probably break the build

[eranif]

Its related to the wx version you are using.
I have fixed this in latest commit