Don't modify argument in place

lib/msf/core/db_manager/exploit_attempt.rb

@@ -43,8 +43,7 @@ module Msf::DBManager::ExploitAttempt
 
     # Look up the service as appropriate
     if port and svc.nil?
-      opts[:proto] ||= prot
-      svc = opts[:service] = get_service(wspace, host, prot, port)
+      svc = get_service(wspace, host, prot, port)
     end
 
     # Look up the host as appropriate
@@ -58,6 +57,9 @@ module Msf::DBManager::ExploitAttempt
 
     # Bail if we dont have a host object
     return if not host
+
+    opts = opts.dup
+    opts[:service] = svc
     opts[:host] = host
 
     do_report_failure_or_success(opts)