Arcus: Override Python_VERSION for debug builds, too

Signed-off-by: Thomas Karl Pietrowski <thopiekar@gmail.com>

libArcus/rules

@@ -34,6 +34,7 @@ override_dh_auto_configure:
 	                      --builddirectory=build-$${PYX}-dbg -- \
 	                      $(CMAKE_COMMON_OPTIONS) \
 	                      -DCMAKE_BUILD_TYPE:STRING="Debug" \
+	                      -DPython_VERSION:STRING="$${PYX}" \
 	                      -DPYTHON_SITE_PACKAGES_DIR:FILEPATH=/usr/lib/python$${PYX}/dist-packages \
 	                      -DPYTHON_EXECUTABLE:FILEPATH=$$(which python$${PYX}) \
 	                      -DCMAKE_INSTALL_LIBDIR=/usr/lib/debug/lib/$(DEB_HOST_MULTIARCH) \