After updating yara to 3.8.1 and libyara3 segfault

Stack trace:

#1  0x00007ffff6bc9653 in yr_scanner_scan_mem_blocks () from /usr/lib/x86_64-linux-gnu/libyara.so.3
#2  0x00007ffff6bc722e in yr_rules_scan_mem_blocks () from /usr/lib/x86_64-linux-gnu/libyara.so.3
#3  0x00007ffff6bc72dc in yr_rules_scan_mem () from /usr/lib/x86_64-linux-gnu/libyara.so.3
#4  0x00007ffff6c0828c in ?? () from /usr/lib/python2.7/dist-packages/yara.x86_64-linux-gnu.so
#5  0x00000000004cb0a5 in PyEval_EvalFrameEx ()
#6  0x00000000004ca1af in PyEval_EvalFrameEx ()
#7  0x00000000004c2bd5 in PyEval_EvalCodeEx ()
#8  0x00000000004c2979 in PyEval_EvalCode ()
#9  0x00000000004f221f in ?? ()
#10 0x00000000004ecae2 in PyRun_FileExFlags ()
#11 0x00000000004eb261 in PyRun_SimpleFileExFlags ()
#12 0x000000000049de78 in Py_Main ()
#13 0x00007ffff6e6ca87 in __libc_start_main (main=0x49d7a0 <main>, argc=3, argv=0x7fffffffe2d8,
    init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fffffffe2c8)
    at ../csu/libc-start.c:310
#14 0x000000000049d6c9 in _start ()

To fix update python-yara if not done so