fix:修正package.json配置自定义编译条件覆盖为false

如果有package.json下的uni-app->scripts配置有两个平台以上且有相同的自定义编译条件变量时且非当前运行平台会导致变量覆盖为true

packages/uni-cli-shared/lib/package.js

@@ -35,7 +35,9 @@ module.exports = {
         if (scriptName !== name) {
           const define = uniAppOptions.scripts[scriptName].define
           Object.keys(define).forEach(name => {
-            if (typeof scriptOptions.define[name] === "undefined") {
+            if (typeof scriptOptions.define[name] !== "undefined") {
+              delete define[name]
+            } else {
               define[name] = false
             }
           })