Remove the date from man pages

It's not something we're keeping up to date anyway.
diff --git a/unix/vncpasswd/vncpasswd.man b/unix/vncpasswd/vncpasswd.man
index b192848..e9250fd 100644
--- a/unix/vncpasswd/vncpasswd.man
+++ b/unix/vncpasswd/vncpasswd.man
@@ -1,4 +1,4 @@
-.TH vncpasswd 1 "09 Jul 2010" "TigerVNC" "Virtual Network Computing"
+.TH vncpasswd 1 "" "TigerVNC" "Virtual Network Computing"
 .SH NAME
 vncpasswd \- change the VNC password
 .SH SYNOPSIS