[#316] locode/boltdb: Add default timeout to open underlying BoltDB instance

Set timeout option of BoltDB Open operation to 3s in order to prevent
indefinite waiting for file lock.

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>

pkg/util/locode/db/boltdb/calls.go

@@ -11,6 +11,8 @@ import (
 )
 
 // Open opens underlying BoltDB instance.
+//
+// Timeout of BoltDB opening is 3s (only for Linux or Darwin).
 func (db *DB) Open() error {
 	// copy-paste from metabase:
 	// consider universal Open/Close for BoltDB wrappers

pkg/util/locode/db/boltdb/opts.go

@@ -2,6 +2,7 @@ package locodebolt
 
 import (
 	"os"
+	"time"
 
 	"go.etcd.io/bbolt"
 )
@@ -18,5 +19,8 @@ type options struct {
 func defaultOpts() *options {
 	return &options{
 		mode: os.ModePerm, // 0777
+		boltOpts: &bbolt.Options{
+			Timeout: 3 * time.Second,
+		},
 	}
 }