[doc] winedev: Signal that 'set +/- foo' only works for debug channels in WINEDEBUG

[Frédéric Delanoy]

---
 en/winedev-debugger.sgml |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/en/winedev-debugger.sgml b/en/winedev-debugger.sgml
index 587a470..b877063 100644
--- a/en/winedev-debugger.sgml
+++ b/en/winedev-debugger.sgml
@@ -2111,7 +2111,8 @@ set $BreakAllThreadsStartup = 1
 	<title>Debug channels</title>
 	<para>
 	  It is possible to turn on and off debug messages as you
-	  are debugging using the set command.
+	  are debugging using the set command (only for debug channels
+	  specified in WINEDEBUG environment variable).
 	  See <xref linkend="debugging"> for more details on debug
 	  channels.
 	</para>
-- 
1.7.6.3