Revert "Land rapid7#8135, Report hosts always add ip to hostname if hostname is blank"

This reverts commit 5a1c7ca, reversing
changes made to d10b3da.

Author: darkbushido

lib/msf/core/db_manager/host.rb

@@ -177,9 +177,7 @@ def report_host(opts)
     end
 
     # Truncate the name field at the maximum field length
-    if opts[:name].blank?
-      opts[:name] = addr
-    else
+    if opts[:name]
       opts[:name] = opts[:name][0,255]
     end