Remove override warning suppression for linux

This isn't a valid gcc flag, and it gives noise like:
cc1plus: note: unrecognized command-line option ‘-Wno-inconsistent-missing-override’ may have been intended to silence earlier diagnostics

Author: tobil4sk

toolchain/linux-toolchain.xml

@@ -44,7 +44,6 @@
   <flag value="-fpic"/>
   <flag value="-fPIC"/>
   <flag value="-Wno-overflow" />
-  <flag value="-Wno-inconsistent-missing-override"/>
   <cppflag value="-Wno-invalid-offsetof" />
   <flag value="-DHX_LINUX"/>
   <flag value="-DRASPBERRYPI=RASPBERRYPI" if="rpi"/>