This commit fixes the evaluation of whether a trade should incur a fee.

Updates to the test script (will follow later) now check that OMNI pair trades are free.  Prior to this change the results were:

Testing a trade against self where the first token is OMNI
   * Executing the trade
   * Verifiying the results
      # Checking no fee was taken...
        * Checking the original trade matches to confirm trading fee was 0...PASS
        * Checking the new trade matches to confirm trading fee was 0...FAIL (result:1)
        * Checking the fee cache is empty for property 1...PASS
        * Checking the fee cache is empty for property 3...FAIL (result:1)
        * Checking the trading address didn't lose any #1 tokens after trade...PASS
        * Checking the trading address didn't lose any #3 tokens after trade...FAIL (result:9999999)

After this change, the same test provides the following results:

Testing a trade against self where the first token is OMNI
   * Executing the trade
   * Verifiying the results
      # Checking no fee was taken...
        * Checking the original trade matches to confirm trading fee was 0...PASS
        * Checking the new trade matches to confirm trading fee was 0...PASS
        * Checking the fee cache is empty for property 1...PASS
        * Checking the fee cache is empty for property 3...PASS
        * Checking the trading address didn't lose any #1 tokens after trade...PASS
        * Checking the trading address didn't lose any #3 tokens after trade...PASS

src/omnicore/mdex.cpp

@@ -263,7 +263,7 @@ static MatchReturnType x_Trade(CMPMetaDEx* const pnew)
 
             // strip a 0.05% fee from non-OMNI pairs if fees are activated
             if (IsFeatureActivated(FEATURE_FEES, pnew->getBlock())) {
-                if ( (pold->getProperty() != (OMNI_PROPERTY_MSC || OMNI_PROPERTY_TMSC)) || (pold->getDesProperty() != (OMNI_PROPERTY_MSC || OMNI_PROPERTY_TMSC)) ) {
+                if (pold->getProperty() > OMNI_PROPERTY_TMSC && pold->getDesProperty() > OMNI_PROPERTY_TMSC) {
                     int64_t feeDivider = 2000; // 0.05%
                     tradingFee = buyer_amountGot / feeDivider;