Puts the custom error handler behind its own define (#40086)

* henk

* wops forgot a commit

* Update world.dm

* Update _logging.dm

* now it works, tested

* Update _compile_options.dm

* Update _compile_options.dm

code/modules/error_handler/error_handler.dm

@@ -1,8 +1,7 @@
 GLOBAL_VAR_INIT(total_runtimes, GLOB.total_runtimes || 0)
 GLOBAL_VAR_INIT(total_runtimes_skipped, 0)
 
-#ifdef DEBUG
-
+#ifdef USE_CUSTOM_ERROR_HANDLER
 #define ERROR_USEFUL_LEN 2
 
 /world/Error(exception/E, datum/e_src)
@@ -128,5 +127,4 @@ GLOBAL_VAR_INIT(total_runtimes_skipped, 0)
 
 	// This writes the regular format (unwrapping newlines and inserting timestamps as needed).
 	log_runtime("runtime error: [E.name]\n[E.desc]")
-
-#endif
+#endif

code/modules/error_handler/error_viewer.dm

@@ -7,7 +7,7 @@
 //   logged errors. Only one instance of this datum should ever exist, and it's
 //   right here:
 
-#ifdef DEBUG
+#ifdef USE_CUSTOM_ERROR_HANDLER
 GLOBAL_DATUM_INIT(error_cache, /datum/error_viewer/error_cache, new)
 #else
 // If debugging is disabled, there's nothing useful to log, so don't bother.
@@ -192,4 +192,4 @@ GLOBAL_DATUM(error_cache, /datum/error_viewer/error_cache)
 	browse_to(user, html)
 
 /datum/error_viewer/error_entry/make_link(linktext, datum/error_viewer/back_to, linear)
-	return is_skip_count ? name : ..()
+	return is_skip_count ? name : ..()