Increase waiting times compat.sh and ssl-opt.sh

- Some of the CI machines don't have lsof installed yet, so rely on an sleeping
an arbitrary number of seconds while the server starts. We're seeing
occasional failures with the current delay because the CI machines are highly
loaded, which seems to indicate the current delay is not quite enough, but
hopefully not to far either, so double it.

- While at it, also double the watchdog delay: while I don't remember seeing
  much failures due to client timeout, this change doesn't impact normal
running time of the script, so better err on the safe side.

These changes don't affect the test and should only affect the false positive
rate coming from the test framework in those scripts.

tests/compat.sh

@@ -879,7 +879,7 @@ if type lsof >/dev/null 2>/dev/null; then
     }
 else
     wait_server_start() {
-        sleep 1
+        sleep 2
     }
 fi
 

tests/ssl-opt.sh

@@ -539,14 +539,28 @@ fi
 # used by watchdog
 MAIN_PID="$$"
 
-# be more patient with valgrind
+# We use somewhat arbitrary delays for tests:
+# - how long do we wait for the server to start (when lsof not available)?
+# - how long do we allow for the client to finish?
+#   (not to check performance, just to avoid waiting indefinitely)
+# Things are slower with valgrind, so give extra time here.
+#
+# Note: without lsof, there is a trade-off between the running time of this
+# script and the risk of spurious errors because we didn't wait long enough.
+# The watchdog delay on the other hand doesn't affect normal running time of
+# the script, only the case where a client or server gets stuck.
 if [ "$MEMCHECK" -gt 0 ]; then
-    START_DELAY=3
-    DOG_DELAY=30
+    START_DELAY=6
+    DOG_DELAY=60
 else
-    START_DELAY=1
-    DOG_DELAY=10
+    START_DELAY=2
+    DOG_DELAY=20
 fi
+
+# some particular tests need more time:
+# - for the client, we multiply the usual watchdog limit by a factor
+# - for the server, we sleep for a number of seconds after the client exits
+# see client_need_more_time() and server_needs_more_time()
 CLI_DELAY_FACTOR=1
 
 # Pick a "unique" server port in the range 10000-19999, and a proxy port