patch 9.0.1594: some internal error messages are translated

Problem:    Some internal error messages are translated.
Solution:   Consistently do not translate internal error messages.
            (closes #12459)

src/alloc.c

@@ -226,7 +226,7 @@ lalloc(size_t size, int message)
     {
 	// Don't hide this message
 	emsg_silent = 0;
-	iemsg(_(e_internal_error_lalloc_zero));
+	iemsg(e_internal_error_lalloc_zero);
 	return NULL;
     }