Fix the header size for the Oceanic VT4 and VT4.1.

This change was already present in the oceanic_atom2_parser_get_field()
function, but not in the oceanic_atom2_parser_samples_foreach()
function. These two should always be kept in sync.

This fixes a bug in the tank pressure detection.

src/oceanic_atom2_parser.c

@@ -456,6 +456,9 @@ oceanic_atom2_parser_samples_foreach (dc_parser_t *abstract, dc_sample_callback_
 
 	// Get the offset to the header sample.
 	unsigned int header = headersize - PAGESIZE / 2;
+	if (parser->model == VT4 || parser->model == VT41) {
+		header = 3 * PAGESIZE;
+	}
 
 	unsigned int time = 0;
 	unsigned int interval = 1;