tests: increase the default server logs lock timeout

This timeout is used to wait for the server to finish writing its logs
before checking them against the expected values. An overloaded machine
could take more than the two seconds previously allocated, so increase
the timeout to 5 seconds.

Ref: #11328
Closes #11834

tests/runner.pm

@@ -126,7 +126,7 @@ our $tortalloc;
 my %oldenv;       # environment variables before test is started
 my $UNITDIR="./unit";
 my $CURLLOG="$LOGDIR/commands.log"; # all command lines run
-my $defserverlogslocktimeout = 2; # timeout to await server logs lock removal
+my $defserverlogslocktimeout = 5; # timeout to await server logs lock removal
 my $defpostcommanddelay = 0; # delay between command and postcheck sections
 my $multiprocess;   # nonzero with a separate test runner process