Fix argument index in stream_select()

Closes GH-7067.

Author: twose

ext/standard/streamsfuncs.c

@@ -794,7 +794,7 @@ PHP_FUNCTION(stream_select)
 			zend_argument_value_error(4, "must be greater than or equal to 0");
 			RETURN_THROWS();
 		} else if (usec < 0) {
-			zend_argument_value_error(4, "must be greater than or equal to 0");
+			zend_argument_value_error(5, "must be greater than or equal to 0");
 			RETURN_THROWS();
 		}