NetworkManager randomly crashed when network connectivity check fails to
connect.

(gdb) bt
#0  0x00007f5a91eb94bb in _int_free () from /lib64/libc.so.6
#1  0x00007f5a9263b901 in ?? () from /usr/lib64/libcurl.so.4
#2  0x00007f5a92649cad in curl_easy_cleanup () from /usr/lib64/libcurl.so.4
#3  0x0000560ecadfc07c in cb_data_free (cb_data=0x560ecc079800,
state=NM_CONNECTIVITY_LIMITED, error=0x0, log_message=0x560ecc082bb0 "check
failed with curl status 7") at src/nm-connectivity.c:209
#4  0x0000560ecadfc285 in _con_curl_check_connectivity (mhandle=0x560ecbff7c40,
sockfd=<optimized out>, ev_bitmask=<optimized out>) at
src/nm-connectivity.c:275
#5  0x0000560ecadfc39d in _con_curl_socketevent_cb (ch=0x560ecc09ef00,
condition=<optimized out>, user_data=0x560ecc0dc960) at
src/nm-connectivity.c:359
#6  0x00007f5a92ba3ea8 in g_main_context_dispatch () from
/usr/lib64/libglib-2.0.so.0
#7  0x00007f5a92ba4298 in ?? () from /usr/lib64/libglib-2.0.so.0
#8  0x00007f5a92ba4592 in g_main_loop_run () from /usr/lib64/libglib-2.0.so.0
#9  0x0000560ecacaf072 in main (argc=<optimized out>, argv=<optimized out>) at
src/main.c:438