deadlock on iOS if launched from a non-main thread too

The same problem mentioned in:

commit 123c7b8044
Date:   Mon May 20 23:53:12 2019 +0300

    tdf#125397: Fixes for threads and SolarMutex on iOS

happens if launched not from the main thread too.

The need for this in either case needs to be looked into a bit
more.

Change-Id: I05deb87897201c3ff14f28fc858c30876f491681
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/190619
Reviewed-by: Skyler Grey <skyler.grey@collabora.com>
Tested-by: Jenkins CollaboraOffice <jenkinscollaboraoffice@gmail.com>
(cherry picked from commit 11967c72b20b27972aa29c246101bb6da39b456a)
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/191315
Tested-by: Caolán McNamara <caolan.mcnamara@collabora.com>
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolan.mcnamara@collabora.com>

desktop/source/lib/init.cxx

@@ -8507,7 +8507,7 @@ static int lo_initialize(LibreOfficeKit* pThis, const char* pAppPath, const char
             desktop::Desktop::GetCommandLineArgs().setHeadless();
 
 #ifdef IOS
-            if (InitVCL() && [NSThread isMainThread])
+            if (InitVCL())
             {
                 static bool bFirstTime = true;
                 if (bFirstTime)