Fix installation error on osx

setup.sh

@@ -140,7 +140,9 @@ git submodule update --init --recursive
 # Find the Python version used by GDB.
 PYVER=$(gdb -batch -q --nx -ex 'pi import platform; print(".".join(platform.python_version_tuple()[:2]))')
 PYTHON+=$(gdb -batch -q --nx -ex 'pi import sys; print(sys.executable)')
+if ! osx; then
 PYTHON+="${PYVER}"
+fi
 
 # Find the Python site-packages that we need to use so that
 # GDB can find the files once we've installed them.