Link boost coroutine_exe against CONAN_LIBS

[sturmf]

This allows boost to be built on Ubuntu 18.04 with older CMake that does not know about newer Boost versions and wouldn't add the boost_context lib to coroutine_exe in the static linking case.

This fixes: #3159

Specify library name and version: lib/1.0

• I've read the guidelines for contributing.
• I've followed the PEP8 style guides for Python code in the recipes.
• I've used the latest Conan client version.
• I've tried at least one configuration locally with the
  conan-center hook activated.

[CLAassistant]

All committers have signed the CLA.

[conan-center-bot]

Sorry, the build is only launched for Early Access Program users. You can request access writing in this issue.

[ghost]

I detected other pull requests that are modifying boost/all recipe:

• [boost] Add 'algorithm' lib #3961 #3963
• Boost/1.72.0/mpi #3959
• boost: patch serialization sources #3918
• Boost: Change assertions to warnings #3900
• [boost] Add nowide lib #3894
• boost: add boost/1.75.0 #3872
• Add --disable-icu flag for iconv backend #3855
• Fix boost syntax warning #3522
• boost: Correct --disable-iconv option #2657
• Boost components #1925
• boost: fix i18n_backend=icu support for version 1.7{1,2,3}.0 #1704

This message is automatically generated by https://github.com/ericLemanissier/conan-center-conflicting-prs so don't hesitate to report issues/improvements there.

[stale]

This pull request has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.