Peg bmx7 dependencies to commits

src/freedombone-image-customise

@@ -850,6 +850,7 @@ make install
 cd /etc
 git clone https://github.com/json-c/json-c.git
 cd json-c
+git checkout 3df1f98b4ab52f271dba5e13ec59cf4d1d093e1a -b 3df1f98b4ab52f271dba5e13ec59cf4d1d093e1a
 sh ./autogen.sh
 ./configure
 if ! make; then
@@ -860,6 +861,7 @@ make install
 cd /etc
 git clone https://git.openwrt.org/project/libubox.git
 cd libubox
+git checkout 3c1b33b7d57ad8b8aeeab8babd48625b86532e0b -b 3c1b33b7d57ad8b8aeeab8babd48625b86532e0b
 cmake .
 if ! make; then
     exit 3