Move fix from 7866a61 into MythCoreContext.

This moves the GetMasterHostName fix from changeset 7866a61 into
MythCoreContext, in the event this is the cause of other similar stalls
in the backend protocol server.

Refs #10265

Author: wagnerrp

mythtv/libs/libmythbase/mythcorecontext.cpp

@@ -846,10 +846,16 @@ QString MythCoreContext::GetMasterHostName(void)
 
     if (d->m_masterHostname.isEmpty())
     {
-        QStringList strlist("QUERY_HOSTNAME");
 
-        if (SendReceiveStringList(strlist))
-            d->m_masterHostname = strlist[0];
+        if (IsMasterBackend())
+            d->m_masterHostname = d->m_localHostname;
+        else
+        {
+            QStringList strlist("QUERY_HOSTNAME");
+
+            if (SendReceiveStringList(strlist))
+                d->m_masterHostname = strlist[0];
+        }
     }
 
     QString ret = d->m_masterHostname;

mythtv/libs/libmythmetadata/videoscan.cpp

@@ -90,9 +90,7 @@ VideoScannerThread::~VideoScannerThread()
 
 void VideoScannerThread::SetDirs(QStringList dirs)
 {
-    QString master = gCoreContext->IsMasterBackend() ? 
-                            gCoreContext->GetHostName() :
-                            gCoreContext->GetMasterHostName();
+    QString master = gCoreContext->GetMasterHostName();
     QStringList searchhosts, mdirs;
     m_offlineSGHosts.clear();