manpage: snd_tinnyfilter is a hidden setting

doc/sopwith.cfg.5

@@ -40,10 +40,6 @@ indicating "false" and a non-zero value indicating "true".
 \fBvid_fullscreen\fR
 If 1, the game runs full screen rather than in a window. By default this is 0.
 .TP
-\fBsnd_tinnyfilter\fR
-If 1, a filter is applied to the sound output so that it sounds more like a
-tinny PC speaker that's inside a metal PC case. By default this is 1.
-.TP
 \fBconf_solidground\fR
 If 1, display the ground as a solid white block, reproducing the visual
 appearance of "Sopwith 1". If 0, the ground is displayed as a line, reproducing
@@ -148,6 +144,10 @@ The following are "hidden settings": they cannot be edited in-game via the
 options menu, and editing the configuration file is the only way to change
 them.
 .TP
+\fBsnd_tinnyfilter\fR
+If 1, a filter is applied to the sound output so that it sounds more like a
+tinny PC speaker that's inside a metal PC case. By default this is 1.
+.TP
 \fBconf_missiles\fR
 Enable missiles and starbursts (flares). This is a feature that was originally
 added by the author of Sopwith in the "Network Edition" release, but has been