REGTEST: increase some short timeouts to make tests more reliable

A few regtests continue to regularly fail in highly loaded VMs because
they have very short timeouts. Actually the goal of running with short
timeouts was to make sure we do not uselessly wait during tests designed
to trigger them, but these timeouts here are never supposed to fire at
all, so they don't need to be kept in the 15-20ms range. They do not
pose any issue on any regular machine, but VMs are often suffering from
huge time jumps and cannot always produce responses in that short of a
time.

Just like with commit ce6fc25b1 ("REGTEST: increase timeouts on the
seamless-reload test"), let's raise these short timeouts to 1 second.
A few other ones remain set to 150-200ms and do not seem to cause any
issue. Some are actually expected to trigger so let's not touch them
for now.
diff --git a/reg-tests/http-rules/map_regm_with_backref.vtc b/reg-tests/http-rules/map_regm_with_backref.vtc
index 502e8d3..4937269 100644
--- a/reg-tests/http-rules/map_regm_with_backref.vtc
+++ b/reg-tests/http-rules/map_regm_with_backref.vtc
@@ -46,9 +46,9 @@
     ${no-htx} option http-use-htx
     log global
     option httplog
-    timeout connect         15ms
-    timeout client          20ms
-    timeout server          20ms
+    timeout connect         1s
+    timeout client          1s
+    timeout server          1s
 
   frontend fe1
     bind "fd@${fe1}"