remove trailing comma for php less then 7.2 compatatibility (#10)

Author: wojsmol

src/AI_Command.php

@@ -343,7 +343,7 @@ private function generate_text( $builder, $assoc_args ) {
 				// @phpstan-ignore class.notFound
 				$token_usage[ TokenUsage::KEY_COMPLETION_TOKENS ],
 				// @phpstan-ignore class.notFound
-				$token_usage[ TokenUsage::KEY_TOTAL_TOKENS ],
+				$token_usage[ TokenUsage::KEY_TOTAL_TOKENS ]
 			),
 			'ai'
 		);