unset mnCount in ScXMLCellFieldSContext::CreateChildContext()

For the syntactically invalid (because <text:s> does not have child
elements and thus unlikely) case that there would be a child element
nevertheless, so we wouldn't import the sequence of spaces multiple
times.

Change-Id: I2b2288aee21f200c9fd2ba961974ef4de074f57e

sc/source/filter/xml/celltextparacontext.cxx

@@ -402,6 +402,7 @@ SvXMLImportContext* ScXMLCellFieldSContext::CreateChildContext(
     if (mnCount)
     {
         PushSpaces();
+        mnCount = 0;
     }
 
     return new SvXMLImportContext(GetImport(), nPrefix, rLocalName);