no https with toolchain URL

Author: BernardXiong

meta-smart/classes/machine.bbclass

@@ -46,17 +46,17 @@ def handle_machine(d):
 def toolchain_for_machine(d):
     toolchains = {
         "aarch64-linux-musleabi-": {
-            "URL": "https://download.rt-thread.org/download/rt-smart/toolchains/aarch64-linux-musleabi_for_x86_64-pc-linux-gnu_latest.tar.bz2",
+            "URL": "http://download.rt-thread.org/download/rt-smart/toolchains/aarch64-linux-musleabi_for_x86_64-pc-linux-gnu_latest.tar.bz2",
             "LOCAL_TC": "aarch64-linux-musleabi-gcc-latest",
             "TARGET_TC": "aarch64-linux-musleabi_for_x86_64-pc-linux-gnu"
         }, 
         "riscv64-linux-musleabi-": {
-            "URL": "https://download.rt-thread.org/download/rt-smart/toolchains/riscv64-linux-musleabi_for_x86_64-pc-linux-gnu_latest.tar.bz2",
+            "URL": "http://download.rt-thread.org/download/rt-smart/toolchains/riscv64-linux-musleabi_for_x86_64-pc-linux-gnu_latest.tar.bz2",
             "LOCAL_TC": "riscv64-linux-musleabi-gcc-latest",
             "TARGET_TC": "riscv64-linux-musleabi_for_x86_64-pc-linux-gnu"
         },
         "arm-linux-musleabi-": {
-            "URL": "https://download.rt-thread.org/download/rt-smart/toolchains/arm-linux-musleabi_for_x86_64-pc-linux-gnu_latest.tar.bz2",
+            "URL": "http://download.rt-thread.org/download/rt-smart/toolchains/arm-linux-musleabi_for_x86_64-pc-linux-gnu_latest.tar.bz2",
             "LOCAL_TC": "arm-linux-musleabi-gcc-latest",
             "TARGET_TC": "arm-linux-musleabi_for_x86_64-pc-linux-gnu"
         }