Enable full hardening build

debian/rules

@@ -1,6 +1,7 @@
 #!/usr/bin/make -f
 
 export CFLAGS:=$(shell dpkg-buildflags --get CFLAGS)
+export DEB_BUILD_MAINT_OPTIONS = hardening=+all
 
 ifeq ($(SOURCE_DATE_EPOCH),)
     # workaround until SOURCE_DATE_EPOCH is available