Fix single quoted string escape

src/basic-languages/mysql/mysql.ts

@@ -862,7 +862,7 @@ export const language = <languages.IMonarchLanguage>{
 			[/"/, { token: 'string.double', next: '@stringDouble' }]
 		],
 		string: [
-			[/[^']+/, 'string'],
+			[/(?:\\'|[^'])+/, 'string'],
 			[/''/, 'string'],
 			[/'/, { token: 'string', next: '@pop' }]
 		],