automap mapping oxygen to carbon atom

When Indigo is configured to allow any bond to be made/broken/order changed, the following example, produces an atom mapping in which an oxygen is mapped to a carbon and a carbon is mapped to an oxygen. I've tested with 1.3.0beta.r16 but this also ocurrs on older versions.

To reproduce:
```java
Indigo indigo = new Indigo();
IndigoObject reaction = indigo.loadReaction("CCOC(=O)C(=C)O[Si](C)(C)C.COC1=CC=C(Br)C=C1C(C)(C)O>>CCOC(=O)C(=O)CC(C)(C)C1=CC(Br)=CC=C1OC");
for (IndigoObject m: reaction.iterateMolecules()){
for (IndigoObject b: m.iterateBonds()){
reaction.setReactingCenter(b, Indigo.RC_UNCHANGED | Indigo.RC_ORDER_CHANGED | Indigo.RC_MADE_OR_BROKEN);
}
}
reaction.automap("discard ignore_charges ignore_valence");
System.out.println(reaction.smiles());
//Gives [CH3:1][CH2:2][O:3][C:4]([C:6]([O:8][Si](C)(C)C)=[CH2:7])=[O:5].[CH3:13][O:14][C:15]1[C:21]([C:22](O)([CH3:24])[CH3:23])=[CH:20][C:18]([Br:19])=[CH:17][CH:16]=1>>[CH3:1][CH2:2][O:3][C:4]([C:6]([CH2:8][C:22]([C:21]1[C:15]([O:14][CH3:13])=[CH:16][CH:17]=[C:18]([Br:19])[CH:20]=1)([CH3:24])[CH3:23])=[O:7])=[O:5]
```