APP in FUCKING ANDROID 7 do not trust user certificate ANYMORE.
DO THIS!

############### Method 1: Edit apk #################################
# ONLY DO THIS for Android 7+

# EDIT AndroidManifest.xml
# https://gaojiajun.cn/2018/08/charles-notTrust-in-android7.0/

apktool d zhixiang-1.3.3_48.apk
# do your job
apktool b zhixiang-1.3.3_48

keytool -genkey -v -keystore keyStore.keystore -alias app -keyalg RSA -keysize 2048 -validity 10000
jarsigner -verbose -sigalg SHA1withRSA -digestalg SHA1 -keystore keyStore.keystore zhixiang-1.3.3_48/dist/zhixiang-1.3.3_48.apk app

############### Method 2: Root #################################
# ONLY DO THIS for Android 7+

rename `cacert.pem` to `<Certificate_Hash>.<Number>` and put into `/system/etc/security/cacerts/`.

How to get hash? Run `openssl x509 -subject_hash_old -in <Certificate_File>`

For detail, please read https://gaojiajun.cn/2018/08/charles-notTrust-in-android7.0/