Can't load 3rd party board support on proxy connection

[greatjp3]

I want to use 3rd party board openCR on proxy connection.
But, can't download board configuration.
proxy set: HTTP, Host name: 10.112.1.184:8080

When i try boards Manager,
In 1.8.8, EVEN default configuration not downloaded.

c:\arduino_debug.exe
Loading configuration...
Initializing packages...
Preparing boards...
Starting...
Using proxy HTTP @ /10.112.1.184:8080
 Error downloading https://downloads.arduino.cc/packages/package_index.json
java.lang.RuntimeException: java.lang.Exception: Error downloading https://downloads.arduino.cc/packages/package_index.json

In 1.8.1, default configuration loaded, but 3rd party configuration not downloaded.

c:\arduino_debug.exe
Loading configuration...
Initializing packages...
Preparing boards...
Starting...
Using proxy HTTP @ /10.112.1.184:8080
Using proxy HTTP @ /10.112.1.184:8080
Using proxy HTTP @ /10.112.1.184:8080
Error downloading https://raw.githubusercontent.com/ROBOTIS-GIT/OpenCR/master/arduino/opencr_release/package_opencr_index.json

As i see, difference between 1.8.1 and 1.8.8 are,
1.8.1 : http://downloads.arduino.cc/packages/package_index.json
1.8.8 : https://downloads.arduino.cc/packages/package_index.json

It means, https proxy are not work properly.

How can i download 3rd board configuration on proxy connection?