Use a single dbus connection object

Starting with sdbusplus 8ca6025, calling bus_new_default multiple times
doesn't seem to work - making calls that generate dbus traffic on one
of the objects results in something like:

  sd_bus_call: System.Error.ENOTCONN: Transport endpoint is not connected

This wasn't ideal anyway - move to a single object, shared
application-wide.

Tested: Booted a witherspoon QEMU image and there were no coredumps
Change-Id: I804a1b1438b22f48e45b26d395135e401ca98a06
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/manager.cpp b/manager.cpp
index f9de91d..69639e4 100644
--- a/manager.cpp
+++ b/manager.cpp
@@ -30,7 +30,7 @@
 const std::set<std::string> Manager::managedProperties = {PROPERTY_TIME_MODE,
                                                           PROPERTY_TIME_OWNER};
 
-Manager::Manager(sdbusplus::bus::bus& bus) : bus(bus)
+Manager::Manager(sdbusplus::bus::bus& bus) : bus(bus), settings(bus)
 {
     using namespace sdbusplus::bus::match::rules;
     hostStateChangeMatch =