Use the currently active locale if no format passed

No format passed doesn't necessarily mean the init/system locale,
use the locale set at SvNumberFormatter::IsNumberFormat()

Change-Id: Ief1025fa14145396ba096842e2f3341496ce4ce8
Reviewed-on: https://gerrit.libreoffice.org/53829Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Eike Rathke <erack@redhat.com>

svl/source/numbers/zforfind.cxx

@@ -709,8 +709,9 @@ bool ImpSvNumberInputScan::GetCurrency( const OUString& rString, sal_Int32& nPos
     if ( rString.getLength() > nPos )
     {
         if ( !aUpperCurrSymbol.getLength() )
-        {   // if no format specified the currency of the initialized formatter
-            LanguageType eLang = (mpFormat ? mpFormat->GetLanguage() : pFormatter->GetLanguage());
+        {   // If no format specified the currency of the currently active locale.
+            LanguageType eLang = (mpFormat ? mpFormat->GetLanguage() :
+                    pFormatter->GetLocaleData()->getLanguageTag().getLanguageType());
             aUpperCurrSymbol = pFormatter->GetCharClass()->uppercase(
                 SvNumberFormatter::GetCurrencyEntry( eLang ).GetSymbol() );
         }