LOK documentLoad needs SolarMutex protection too.

We probably need to do this for most of LOK now that
we use soffice_main.

Change-Id: I77be7865511c083679cf2f68b0e5df106506fd70

desktop/source/lib/init.cxx

@@ -276,6 +276,8 @@ static LibreOfficeKitDocument* lo_documentLoad(LibreOfficeKit* pThis, const char
 
     OUString aURL = getAbsoluteURL(pURL);
 
+    SolarMutexGuard aGuard;
+
     uno::Reference<frame::XDesktop2> xComponentLoader = frame::Desktop::create(xContext);
 
     pLib->maLastExceptionMsg = "";