Add EHOSTUNREACH ('No route to host') to the errnos trapped by transient_internet().
diff --git a/Lib/test/support.py b/Lib/test/support.py
index fb15d64..152cac9 100644
--- a/Lib/test/support.py
+++ b/Lib/test/support.py
@@ -800,6 +800,7 @@
     default_errnos = [
         ('ECONNREFUSED', 111),
         ('ECONNRESET', 104),
+        ('EHOSTUNREACH', 113),
         ('ENETUNREACH', 101),
         ('ETIMEDOUT', 110),
     ]