qemu: Change the default unix monitor timeout

There is a number of reported issues when we fail starting a domain.
Turns out that, in some scenarios like high load, 3 second timeout is
not enough for qemu to start up to the phase where the socket is
created.  Since there is no downside of waiting longer, raise the
timeout right to 30 seconds.

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
(cherry picked from commit fe89b687a02d1a8e1dce695a67b4f9d2c254d7b9)

src/qemu/qemu_monitor.c

@@ -268,7 +268,7 @@ qemuMonitorOpenUnix(const char *monitor, pid_t cpid)
 {
     struct sockaddr_un addr;
     int monfd;
-    int timeout = 3; /* In seconds */
+    int timeout = 30; /* In seconds */
     int ret;
     size_t i = 0;