Issue with neovim's inccommand

[Irubataru]

If you in neovim set inccommand to nosplit and run async and then try to do a substitute command while the asyncrun is still working it will error.

To reproduce

1. Install asyncrun as the only plugin
2. Add the following minimal configuration

set nocompatible
filetype plugin on
set inccommand=nosplit

3. Open vim and run :AsyncRun sleep 100
4. Type :%s/ and it will error

Error message

Error detected while processing function AsyncRun_Job_OnTimer[11]..<SNR>10_AsyncRun_Job_Update:
line   56:
E171: Missing :endif
E171: Missing :endif
...

Version

NVIM v0.5.0-dev
Build type: RelWithDebInfo
Lua 5.1
Compilation: /usr/bin/cc -g -O2
  -fdebug-prefix-map=/build/neovim-7H5ISl/neovim-0.5.0+ubuntu1+git202005062024-f04a9a2-00e710e=.
  -fstack-protector-strong -Wformat -Werror=format-security -U_FORTIFY_SOURCE
  -D_FORTIFY_SOURCE=1 -O2 -g -Og -g -Wall -Wextra -pedantic -Wno-unused-parameter
  -Wstrict-prototypes -std=gnu99 -Wshadow -Wconversion -Wmissing-prototypes
  -Wimplicit-fallthrough -Wvla -fstack-protector-strong -fno-common
  -fdiagnostics-color=auto -DINCLUDE_GENERATED_DECLARATIONS -D_GNU_SOURCE
  -DNVIM_MSGPACK_HAS_FLOAT32 -DNVIM_UNIBI_HAS_VAR_FROM -DMIN_LOG_LEVEL=3
  -I/build/neovim-7H5ISl/neovim-0.5.0+ubuntu1+git202005062024-f04a9a2-00e710e/build/config
  -I/build/neovim-7H5ISl/neovim-0.5.0+ubuntu1+git202005062024-f04a9a2-00e710e/src
  -I/build/neovim-7H5ISl/neovim-0.5.0+ubuntu1+git202005062024-f04a9a2-00e710e/.deps/usr/include
  -I/usr/include
  -I/build/neovim-7H5ISl/neovim-0.5.0+ubuntu1+git202005062024-f04a9a2-00e710e/build/src/nvim/auto
  -I/build/neovim-7H5ISl/neovim-0.5.0+ubuntu1+git202005062024-f04a9a2-00e710e/build/include
Compiled by buildd@lgw01-amd64-048