travis: temporarily disable the forknotify test

It appears to be breaking randomly on Windows

qa/pull-tester/rpc-tests.sh

@@ -13,7 +13,7 @@ export BITCOIND=${REAL_BITCOIND}
 if [ "x${ENABLE_BITCOIND}${ENABLE_UTILS}${ENABLE_WALLET}" = "x111" ]; then
   ${BUILDDIR}/qa/rpc-tests/wallet.sh "${BUILDDIR}/src"
   ${BUILDDIR}/qa/rpc-tests/listtransactions.py --srcdir "${BUILDDIR}/src"
-  ${BUILDDIR}/qa/rpc-tests/forknotify.py --srcdir "${BUILDDIR}/src"
+  #${BUILDDIR}/qa/rpc-tests/forknotify.py --srcdir "${BUILDDIR}/src"
 else
   echo "No rpc tests to run. Wallet, utils, and bitcoind must all be enabled"
 fi