patch 8.2.4273: the EBCDIC support is outdated

Problem:    The EBCDIC support is outdated.
Solution:   Remove the EBCDIC support.
diff --git a/src/map.c b/src/map.c
index 8d60eee..e45ea75 100644
--- a/src/map.c
+++ b/src/map.c
@@ -2018,7 +2018,7 @@
 	{
 	    if (what == 2)
 	    {
-		if (fprintf(fd, IF_EB("\\\026\n", "\\" CTRL_V_STR "\n")) < 0)
+		if (fprintf(fd, "\\\026\n") < 0)
 		    return FAIL;
 	    }
 	    else