Remove the date from man pages

It's not something we're keeping up to date anyway.
diff --git a/vncviewer/vncviewer.man b/vncviewer/vncviewer.man
index 507f629..4fec9eb 100644
--- a/vncviewer/vncviewer.man
+++ b/vncviewer/vncviewer.man
@@ -1,4 +1,4 @@
-.TH vncviewer 1 "05 May 2004" "TigerVNC" "Virtual Network Computing"
+.TH vncviewer 1 "" "TigerVNC" "Virtual Network Computing"
 .SH NAME
 vncviewer \- VNC viewer for X
 .SH SYNOPSIS