Coverage: do not include test-rebind in coverage builds.

Because it invokes the Tor mainloop, it does unpredictable things to
test coverage of a lot of code that it doesn't actually test at
all.  (It is more an integration test than anything else.)

src/test/include.am

@@ -32,8 +32,15 @@ endif
 
 if USEPYTHON
 TESTSCRIPTS += src/test/test_ntor.sh src/test/test_hs_ntor.sh src/test/test_bt.sh
+
+if COVERAGE_ENABLED
+# ...
+else
+# Only do this when coverage is not on, since it invokes lots of code
+# in a kind of unpredictable way.
 TESTSCRIPTS += src/test/test_rebind.sh
 endif
+endif
 
 TESTS += src/test/test src/test/test-slow src/test/test-memwipe \
 	src/test/test_workqueue \