增加文件是否存在的判断

mpmaster/src/main/java/com/xypower/mpmaster/AppMaster.java

@@ -105,7 +105,7 @@ public class AppMaster {
                 final Context context = mService.getApplicationContext();
                 String appPath = MicroPhotoContext.buildAppDir(context);
                 File mpappDb = new File(appPath + "data/App.db");
-                if (System.currentTimeMillis() - mpappDb.lastModified() > 1800000) {
+                if (!mpappDb.exists() || ((System.currentTimeMillis() - mpappDb.lastModified()) > 1800000)) {
                     // greater than 30m
                     MicroPhotoContext.restartMpApp(context);
                 }