fix: Prevent deadlock with database connections (#18)

An embarrassing oopsie on my part: a connection was acquired before
trying to acquire a second connection, instead of after the connection
had been closed.

Author: shrink

Diff for: pg.go

@@ -44,14 +44,6 @@ func NewPostgresHandlesProvider(config *pgxpool.Config, didsTable string, domain
 }
 
 func (pg *PostgresHandles) GetDecentralizedIDForHandle(ctx context.Context, handle Handle) (DecentralizedID, error) {
-	connection, err := pg.pool.Acquire(ctx)
-
-	defer connection.Release()
-
-	if err != nil {
-		return "", err
-	}
-
 	canProvide, err := pg.CanProvideForDomain(ctx, handle.Domain)
 
 	if err != nil {
@@ -62,6 +54,14 @@ func (pg *PostgresHandles) GetDecentralizedIDForHandle(ctx context.Context, hand
 		return "", &CannotGetHandelsFromDomainError{domain: handle.Domain}
 	}
 
+	connection, err := pg.pool.Acquire(ctx)
+
+	defer connection.Release()
+
+	if err != nil {
+		return "", err
+	}
+
 	var did DecentralizedID
 
 	query := fmt.Sprintf(