Fix bug with FFI bindings of sock:setopt().

src/pre_generated-zmq.nobj.c

@@ -1992,7 +1992,7 @@ static const char *zmq_ffi_lua_code[] = { "local ffi=require\"ffi\"\n"
 "	setmetatable(option_sets,{__index = function(tab,opt)\n"
 "		local opt_name = opt_name[opt]\n"
 "		if not opt_name then return nil end\n"
-"		local method = methods[opt_name] or methods['set_' .. opt_name]\n"
+"		local method = methods['set_' .. opt_name] or methods[opt_name]\n"
 "		rawset(tab, opt, method)\n"
 "		return method\n"
 "	end})\n"

src/socket.nobj.lua

@@ -472,7 +472,7 @@ do
 	setmetatable(option_sets,{__index = function(tab,opt)
 		local opt_name = opt_name[opt]
 		if not opt_name then return nil end
-		local method = methods[opt_name] or methods['set_' .. opt_name]
+		local method = methods['set_' .. opt_name] or methods[opt_name]
 		rawset(tab, opt, method)
 		return method
 	end})