Fix debug output. Don't add bool to strings.

scripts.cpp

@@ -366,7 +366,7 @@ void ScriptExplore::init() {
         "Explorer will find nearest unknown when out of known sectors to "
         "explore";
   }
-  BUGZ_LOG(warning) << "Prefer Ports: " + prefer_ports;
+  BUGZ_LOG(warning) << "Prefer Ports: " << prefer_ports;
 }
 
 void ScriptExplore::activate() {