Fix assertion to check the right thing

We want to assert that the token separator character is not one of the
quote pair characters.

Change-Id: Ic6114238f4a45a4f1ed7d255e7e9da3519479148

sc/source/core/tool/stringutil.cxx

@@ -348,7 +348,7 @@ bool ScStringUtil::parseSimpleNumber(
 sal_Int32 ScStringUtil::GetQuotedTokenCount(const OUString &rIn, const OUString& rQuotedPairs, sal_Unicode cTok )
 {
     assert( !(rQuotedPairs.getLength()%2) );
-    assert( rQuotedPairs.indexOf(cTok) );
+    assert( rQuotedPairs.indexOf(cTok) == -1 );
 
     // empty string: TokenCount is 0 per definition
     if ( rIn.isEmpty() )