Fixed crash from broken plugin loaded hook input from global

Fixes #35

CHANGELOG.md

@@ -6,6 +6,9 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## Unreleased
 
+### Fixed
+- crash from broken plugin loaded hook input from global
+
 ## 3.3 - 2019-03-27
 
 ### Added

src/Record/Collector/Plugin_Load_Collector.php

@@ -32,9 +32,16 @@ class Plugin_Load_Collector implements Record_Collector_Interface {
 	 *
 	 * @param string $plugin Plugin file path.
 	 */
-	public function plugin_loaded( string $plugin ): void {
+	public function plugin_loaded( $plugin ): void {
 
 		$time = microtime( true );
+
+		if ( ! is_string( $plugin ) ) { // Broken hook input from global.
+			$this->last = $time;
+
+			return;
+		}
+
 		$this->entries[] = [
 			'name'     => $plugin,
 			'origin'   => $this->last,