dump server longs on hang corrupt dump fuzzer test

recently there are some incidents of hanged tests in the CI
when we try to reproduce them, we get an assertion, not a hang.
maybe the server logs will reveal some info.

tests/integration/corrupt-dump-fuzzer.tcl

@@ -160,6 +160,10 @@ foreach sanitize_dump {no yes} {
                         set err [format "%s" $err] ;# convert to string for pattern matching
                         if {[string match "*SIGTERM*" $err]} {
                             puts "payload that caused test to hang: $printable_dump"
+                            if {$::dump_logs} {
+                                set srv [get_srv 0]
+                                dump_server_log $srv
+                            }
                             exit 1
                         }
                         # if the server terminated update stats and restart it