descriptions: remove unneeded false :new flags

It is the default

doc/descriptions/epson.desc

@@ -11,7 +11,6 @@
 
 :backend "epson"                  ; name of backend
 :version "0.2.42 (unmaintained)"  ; version of backend
-:new :no
 :manpage "sane-epson"             ; name of manpage (if it exists)
 :url "http://www.khk.net/sane"    ; backend's web page
 

doc/descriptions/epson2.desc

@@ -8,7 +8,6 @@
 ; distributed with "Image Scan!" and released under GPL.
 
 :backend "epson2"
-:new :no
 :manpage "sane-epson2"
 
 :devicetype :scanner

doc/descriptions/epsonds.desc

@@ -7,7 +7,6 @@
 
 :backend "epsonds"
 :version "1.0.18 (unmaintained)"
-:new :no
 :manpage "sane-epsonds"
 
 :devicetype :scanner

doc/descriptions/pieusb.desc

@@ -11,7 +11,6 @@
 
 :backend "pieusb"                 ; name of backend
 :version "1.0 (unmaintained)"     ; version of backend
-:new :no
 :manpage "sane-pieusb"            ; name of manpage (if it exists)
 :url "https://github.com/kkaempf/sane-backends"  ; backend's web page