Fix CDT debugger settings on Linux - remove .exe suffix
Fix CDT debugger settings on Linux - remove .exe suffix

On Linux machines arm-none-eabi-gdb executable do not have .exe suffix.
On Windows machines - it is possible to run an executable without explicit .exe suffix.
This change fixes debugger settings for Linux hosts

CalSol/mbed,betzw/mbed-os,svogl/mbed-os,kjbracey-arm/mbed,catiedev/mbed-os,YarivCol/mbed-os,catiedev/mbed-os,infinnovation/mbed-os,mbedmicro/mbed,svogl/mbed-os,kjbracey-arm/mbed,karsev/mbed-os,betzw/mbed-os,nRFMesh/mbed-os,mazimkhan/mbed-os,CalSol/mbed,YarivCol/mbed-os,ryankurte/mbed-os,CalSol/mbed,HeadsUpDisplayInc/mbed,c1728p9/mbed-os,svogl/mbed-os,Archcady/mbed-os,HeadsUpDisplayInc/mbed,andcor02/mbed-os,kjbracey-arm/mbed,karsev/mbed-os,mbedmicro/mbed,karsev/mbed-os,betzw/mbed-os,andcor02/mbed-os,c1728p9/mbed-os,mbedmicro/mbed,mazimkhan/mbed-os,HeadsUpDisplayInc/mbed,catiedev/mbed-os,svogl/mbed-os,YarivCol/mbed-os,mazimkhan/mbed-os,YarivCol/mbed-os,mazimkhan/mbed-os,andcor02/mbed-os,Archcady/mbed-os,andcor02/mbed-os,ryankurte/mbed-os,Archcady/mbed-os,betzw/mbed-os,svogl/mbed-os,c1728p9/mbed-os,kjbracey-arm/mbed,nRFMesh/mbed-os,ryankurte/mbed-os,betzw/mbed-os,betzw/mbed-os,nRFMesh/mbed-os,CalSol/mbed,ryankurte/mbed-os,mazimkhan/mbed-os,karsev/mbed-os,svogl/mbed-os,catiedev/mbed-os,CalSol/mbed,mazimkhan/mbed-os,YarivCol/mbed-os,HeadsUpDisplayInc/mbed,karsev/mbed-os,Archcady/mbed-os,infinnovation/mbed-os,Archcady/mbed-os,nRFMesh/mbed-os,CalSol/mbed,catiedev/mbed-os,Archcady/mbed-os,infinnovation/mbed-os,nRFMesh/mbed-os,c1728p9/mbed-os,ryankurte/mbed-os,HeadsUpDisplayInc/mbed,mbedmicro/mbed,ryankurte/mbed-os,infinnovation/mbed-os,andcor02/mbed-os,catiedev/mbed-os,HeadsUpDisplayInc/mbed,andcor02/mbed-os,infinnovation/mbed-os,c1728p9/mbed-os,YarivCol/mbed-os,nRFMesh/mbed-os,mbedmicro/mbed,c1728p9/mbed-os,karsev/mbed-os,infinnovation/mbed-os