patch 8.2.2047: Amiga: FEAT_ARP defined when it should not

Problem:    Amiga: FEAT_ARP defined when it should not.
Solution:   Adjust #ifdef. (Ola Söder, closes #7370)
diff --git a/src/feature.h b/src/feature.h
index 0c68f79..028eebc 100644
--- a/src/feature.h
+++ b/src/feature.h
@@ -1089,11 +1089,11 @@
 /*
  * +ARP			Amiga only. Use arp.library, DOS 2.0 is not required.
  */
-#if !defined(NO_ARP) && !defined(__amigaos4__)
+#if defined(AMIGA) && !defined(NO_ARP) && !defined(__amigaos4__) \
+	&& !defined(__MORPHOS__) || !defined(__AROS__)
 # define FEAT_ARP
 #endif
 
-
 /*
  * +ole			Win32 OLE automation: Use Makefile.ovc.
  */