Create required dirs after dropping privileges, ensuring correct
ownership. Based on https://github.com/nzbgetcom/nzbget/pull/345.

Index: tests/main/OptionsTest.cpp
--- tests/main/OptionsTest.cpp.orig
+++ tests/main/OptionsTest.cpp
@@ -80,6 +80,8 @@ BOOST_AUTO_TEST_CASE(OptionsInitWithoutConfigurationFi
 {
 	Options options(nullptr, nullptr);
 
+	options.CheckDirs();
+
 	BOOST_CHECK(options.GetConfigFilename() == nullptr);
 #ifdef WIN32
 	BOOST_CHECK(strcmp(options.GetTempDir(), "nzbget/tmp") == 0);
