patch 8.2.0747: cannot forcefully close all popups

Problem:    Cannot forcefully close all popups.
Solution:   Add the "force" argument to popup_clear().  Use it after running a
            test.  Put back the check for a popup when editing a file.
diff --git a/src/channel.c b/src/channel.c
index 0e432f9..1fcb845 100644
--- a/src/channel.c
+++ b/src/channel.c
@@ -156,9 +156,9 @@
     if (log_fd != NULL)
     {
 	if (*fname != NUL)
-	    ch_log(NULL, "closing, opening %s", fname);
+	    ch_log(NULL, "closing this logfile, opening %s", fname);
 	else
-	    ch_log(NULL, "closing");
+	    ch_log(NULL, "closing logfile");
 	fclose(log_fd);
     }