Update Python bindings C compiler.

3 jobs for develop in 1 minute and 59 seconds
Name Stage Failure
failed
pythonbindings Test There is an unknown failure, please try again
./src/util/list.c:46:28: error: invalid conversion from ‘void*’ to ‘ListNode* {aka listNode*}’ [-fpermissive]
ListNode *node = calloc(1, sizeof(ListNode));
^
./src/util/list.c: In function ‘void List_unshift(List*, const void*)’:
./src/util/list.c:76:28: error: invalid conversion from ‘void*’ to ‘ListNode* {aka listNode*}’ [-fpermissive]
ListNode *node = calloc(1, sizeof(ListNode));
^
error: command 'g++-5' failed with exit status 1
ERROR: Build failed: exit status 1