p2p: Make timeout mockable and type safe, speed up test

test/functional/test_framework/util.py

@@ -378,10 +378,10 @@ def write_config(config_path, *, n, chain, extra_config="", disable_autoconnect=
         f.write("fixedseeds=0\n")
         f.write("listenonion=0\n")
         # Increase peertimeout to avoid disconnects while using mocktime.
-        # peertimeout is measured in wall clock time, so setting it to the
-        # duration of the longest test is sufficient. It can be overridden in
-        # tests.
-        f.write("peertimeout=999999\n")
+        # peertimeout is measured in mock time, so setting it large enough to
+        # cover any duration in mock time is sufficient. It can be overridden
+        # in tests.
+        f.write("peertimeout=999999999\n")
         f.write("printtoconsole=0\n")
         f.write("upnp=0\n")
         f.write("natpmp=0\n")