replace deprecated rollup-plugin-terser with @rollup/plugin-terser

Author: yairEO

rollup.config.prod.js

@@ -1,5 +1,5 @@
 import babel           from '@rollup/plugin-babel'
-import { terser }      from 'rollup-plugin-terser'
+import terser          from '@rollup/plugin-terser';
 import cleanup         from 'rollup-plugin-cleanup'
 import { nodeResolve } from '@rollup/plugin-node-resolve'
 import commonjs        from '@rollup/plugin-commonjs'