fix: neat_js exclude

delete operator previously remove reference including 'options.exclude',
use Object.assign to clone 'options' object to prevent that.
https://stackoverflow.com/a/33053362

lib/filter.js

@@ -72,14 +72,14 @@ function logicJs (str, data) {
   }
 
   // Terser doesn't like unsupported options
-  delete options.enable
-  delete options.exclude
-  let jsLogger = options.logger
-  delete options.logger
+	const jsOptions = Object.assign({}, options)
+  delete jsOptions.enable
+  delete jsOptions.exclude
+  delete jsOptions.logger
 
-  let result = Terser.minify(str, options)
+  let result = Terser.minify(str, jsOptions)
   let saved = ((str.length - result.code.length) / str.length * 100).toFixed(2)
-  if (jsLogger) {
+  if (options.logger) {
     let log = hexo.log || console.log
     log.log('Minify the js: %s [%s saved]', path, saved + '%')
   }