increase DH_COMPAT to avoid deprecation warnings

debian/rules

@@ -6,7 +6,7 @@
 #export DH_VERBOSE=1
 
 # This is the debhelper compatibility version to use.
-export DH_COMPAT=4
+export DH_COMPAT=5
 
 package := gkrellm-multiping
 prefix := $(shell pwd)/debian/$(package)