pidgin: explicitly disable nss

* sometimes it leaks from meta-chromium and breaks pidgin build

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>

meta-oe/recipes-support/pidgin/pidgin_2.7.9.bb

@@ -1,5 +1,5 @@
 require pidgin.inc
-PR = "${INC_PR}.1"
+PR = "${INC_PR}.2"
 
 DEPENDS += "farsight2 libidn"
 
@@ -19,4 +19,5 @@ EXTRA_OECONF += "\
   --disable-meanwhile \
   --disable-nm \
   --disable-screensaver \
+  --enable-nss=no \
 "