Remove unused description.

This description isn't used anywhere, and it doesn't contain
much useful information.

lib/libvmod_debug/vmod.vcc

@@ -33,10 +33,8 @@ DESCRIPTION
 This vmod is used to develop, test and debug the various aspects
 of VMOD handling in Varnish.
 
-$Init init_function
-
-Call this whenever a VCL is loaded which imports this vmod.
 
+$Init init_function
 $Function VOID panic(STRING_LIST)
 
 Don't.