Revert "Fix addr space word size encoding"

This reverts commit f638f9d.

The bug that f638f9d had fixed was fixed differently upstream: the
decoder was adjusted to read a signed integer in
5604178194cb55ddb8526f843466d485ed8a36e6.

Reverting this patch to be consistent with upstream.

Author: mborgerson

pypcode/sleigh/sleighbase.cc

@@ -199,7 +199,7 @@ void SleighBase::encodeSlaSpace(Encoder &encoder,AddrSpace *spc) const
 //    encoder.writeSignedInteger(sla::ATTRIB_DEADCODEDELAY, spc->getDeadcodeDelay());
   encoder.writeSignedInteger(sla::ATTRIB_SIZE, spc->getAddrSize());
   if (spc->getWordSize() > 1)
-    encoder.writeUnsignedInteger(sla::ATTRIB_WORDSIZE, spc->getWordSize());
+    encoder.writeSignedInteger(sla::ATTRIB_WORDSIZE, spc->getWordSize());
   encoder.writeBool(sla::ATTRIB_PHYSICAL, spc->hasPhysical());
   if (spc->getType() == IPTR_INTERNAL)
     encoder.closeElement(sla::ELEM_SPACE_UNIQUE);