spnego: fix indent (use 2 spaces) and modelines

Change-Id: I077c21eb213435e7ed0e9ac0b9a8f95aa9dd6f3d
Reviewed-on: https://code.wireshark.org/review/18075
Petri-Dish: Michael Mann <mmann78@netscape.net>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Michael Mann <mmann78@netscape.net>

epan/dissectors/asn1/spnego/spnego.cnf

@@ -177,3 +177,16 @@ NegotiationToken
   }
 
 #.END
+
+#
+# Editor modelines  -  http://www.wireshark.org/tools/modelines.html
+#
+# Local variables:
+# c-basic-offset: 2
+# tab-width: 8
+# indent-tabs-mode: nil
+# End:
+#
+# vi: set shiftwidth=2 tabstop=8 expandtab:
+# :indentSize=2:tabSize=8:noTabs=true:
+#