patch 9.0.0977: it is not easy to see what client-server commands are doing

Problem:    It is not easy to see what client-server commands are doing.
Solution:   Add channel log messages if ch_log() is available.  Move the
            channel logging and make it available with the +eval feature.
diff --git a/src/term.c b/src/term.c
index 9a45f46..40728f2 100644
--- a/src/term.c
+++ b/src/term.c
@@ -2641,7 +2641,7 @@
 	len = out_pos;
 	out_pos = 0;
 	ui_write(out_buf, len, FALSE);
-#ifdef FEAT_JOB_CHANNEL
+#ifdef FEAT_EVAL
 	if (ch_log_output != FALSE)
 	{
 	    out_buf[len] = NUL;