MEDIUM: proxy: remove start_proxies()

Its sole remaining purpose was to display "proxy foo started", which
has little benefit and pollutes output for those with plenty of proxies.
Let's remove it now.

The VTCs were updated to reflect this, because many of them had explicit
counts of dropped lines to match this message.

This is tagged as MEDIUM because some users may be surprized by the
loss of this quite old message.
diff --git a/reg-tests/log/load_balancing.vtc b/reg-tests/log/load_balancing.vtc
index 765ce61..a897877 100644
--- a/reg-tests/log/load_balancing.vtc
+++ b/reg-tests/log/load_balancing.vtc
@@ -30,9 +30,9 @@
 # Here are the syslog messages received by Slg_2:
 syslog Slg_2 -level info {
     recv
-    expect ~ "[^:\\[ ]\\[${h1_pid}\\]: .* \"GET /client_c7 HTTP/1.1\""
+    expect ~ "[^:\\[ ]\\[${h1_pid}\\]: .* \"GET /client_c6 HTTP/1.1\""
     recv
-    expect ~ "[^:\\[ ]\\[${h1_pid}\\]: .* \"GET /client_c10 HTTP/1.1\""
+    expect ~ "[^:\\[ ]\\[${h1_pid}\\]: .* \"GET /client_c8 HTTP/1.1\""
 } -repeat 50 -start
 
 haproxy h1 -conf {