Handle SdBusError exception in setting NTP

sdbusplus now throws SdBusError exception when a sd bus call fails.
When setting NTP via systemd timedatectl service, it may potentially
fail.
So handle this exception.

Also fix a typo in logging, where it should use `=` in meta.

Change-Id: I6c5669b7f06cef47c8d62cb0cbcb0c7fbd2a46e7
Tested: Verify it sets NTP setting OK.
diff --git a/manager.cpp b/manager.cpp
index 1145d33..8d3d955 100644
--- a/manager.cpp
+++ b/manager.cpp
@@ -194,14 +194,16 @@
     method.append(isNtp, false); // isNtp: 'true/false' means Enable/Disable
                                  // 'false' meaning no policy-kit
 
-    if (bus.call(method))
+    try
     {
+        bus.call_noreply(method);
         log<level::INFO>("Updated NTP setting",
-                         entry("ENABLED:%d", isNtp));
+                         entry("ENABLED=%d", isNtp));
     }
-    else
+    catch (const sdbusplus::exception::SdBusError& ex)
     {
-        log<level::ERR>("Failed to update NTP setting");
+        log<level::ERR>("Failed to update NTP setting",
+                        entry("ERR=%s", ex.what()));
     }
 }