Use consistent zeek_init priority for Log::create_stream calls

Typically in base scripts, Log::create_stream() is called in zeek_init()
handler with &priority=5 such that it will have already been created
in the default zeek_init() &priority=0.

scripts/base/frameworks/signatures/main.zeek

@@ -140,7 +140,7 @@ global count_per_orig: table[addr, string] of count
 global did_sig_log: set[string] &read_expire = 1 hr;
 
 
-event zeek_init()
+event zeek_init() &priority=5
 	{
 	Log::create_stream(Signatures::LOG, [$columns=Info, $ev=log_signature, $path="signatures"]);
 	}