* seastar 0303e0c...e534401 (6):
> Merge "enable rpc to work on non contiguous memory for receive" from Gleb
> install-dependencies.sh: install python3 for Ubuntu/Debian, which requires for configure.py
> fix tcp stuck when output_stream write more than 212992 bytes once.
> scripts/posix_net_conf.sh: supress 'ls: cannot access /sys/class/net/<NIC>/device/msi_irqs/' error message
> scripts/posix_net_conf.sh: fix 'command not found' error when specifies --cpu-mask
> native_network_stack: Fix use after free/missing wait in dhcp
Includes: "Remove utils::fragmented_input_stream and utils::input_stream in favor of seastar version" from Gleb.