Tweak zero_length_keys.sh and test/include.am to make out-of-tree builds work

src/test/include.am

@@ -122,7 +122,7 @@ if USEPYTHON
 	./src/test/test-bt-cl assert | $(PYTHON) $(top_srcdir)/src/test/bt_test.py
 	./src/test/test-bt-cl crash | $(PYTHON) $(top_srcdir)/src/test/bt_test.py
 endif
-	./src/test/zero_length_keys.sh
+	$(top_srcdir)/src/test/zero_length_keys.sh
 
 EXTRA_DIST += \
 	src/test/bt_test.py \

src/test/zero_length_keys.sh

@@ -26,7 +26,9 @@ if [ $# -lt 1 ]; then
 fi
 
 export DATA_DIR=`mktemp -d -t tor_zero_length_keys`
-TOR="src/or/tor --hush --DisableNetwork 1 --ShutdownWaitLength 0 --ORPort 12345"
+# DisableNetwork means that the ORPort won't actually be opened.
+# 'ExitRelay 0' suppresses a warning.
+TOR="./src/or/tor --hush --DisableNetwork 1 --ShutdownWaitLength 0 --ORPort 12345 --ExitRelay 0"
 
 if [ -s "$DATA_DIR"/keys/secret_id_key -a -s "$DATA_DIR"/keys/secret_onion_key -a -s "$DATA_DIR"/keys/secret_onion_key_ntor ]; then
   echo "Failure: Previous tor keys present in tor data directory"