vagrant: fix vagrant scp on macOS, fixes #5921

it did not find pyenv in PATH, resulting in unpretty error messages.

Vagrantfile

@@ -207,6 +207,8 @@ def install_pyenv(boxname)
     . ~/.bash_profile
     curl -s -L https://raw.githubusercontent.com/yyuu/pyenv-installer/master/bin/pyenv-installer | bash
     echo 'eval "$(pyenv init --path)"' >> ~/.bash_profile
+    echo 'export PYENV_ROOT="$HOME/.pyenv"' >> ~/.bashrc
+    echo 'export PATH="$PYENV_ROOT/bin:$PATH"' >> ~/.bashrc
     echo 'eval "$(pyenv init -)"' >> ~/.bashrc
     echo 'eval "$(pyenv virtualenv-init -)"' >> ~/.bashrc
   EOF