Fix errorneously creating a symlink inside env directory if running with -f (#496)

bin/pyenv-activate

@@ -22,10 +22,8 @@ fi
 
 { printf "\x1B[31;1m"
   echo
-  echo "Failed to activate virtualenv."
-  echo
-  echo "Perhaps pyenv-virtualenv has not been loaded into your shell properly."
-  echo "Please restart current shell and try again."
+  echo "\`pyenv activate' requires Pyenv and Pyenv-Virtualenv to be loaded into your shell."
+  echo "Check your shell configuration and Pyenv and Pyenv-Virtualenv installation instructions."
   echo
   printf "\x1B[0m"
 } 1>&2

bin/pyenv-deactivate

@@ -11,10 +11,8 @@ set -e
 
 { printf "\x1B[31;1m"
   echo
-  echo "Failed to deactivate virtualenv."
-  echo
-  echo "Perhaps pyenv-virtualenv has not been loaded into your shell properly."
-  echo "Please restart current shell and try again."
+  echo "\`pyenv deactivate' requires Pyenv and Pyenv-Virtualenv to be loaded into your shell."
+  echo "Check your shell configuration and Pyenv and Pyenv-Virtualenv installation instructions."
   echo
   printf "\x1B[0m"
 } 1>&2

bin/pyenv-virtualenv

@@ -631,7 +631,8 @@ fi
 
 ## Create symlink in the `versions` directory for backward compatibility
 if [ -d "${VIRTUALENV_PATH}" ] && [ -n "${COMPAT_VIRTUALENV_PATH}" ]; then
-  ln -fs "${VIRTUALENV_PATH}" "${COMPAT_VIRTUALENV_PATH}"
+  # Overwrite an existing link, can happen if running with -f
+  ln -fsn "${VIRTUALENV_PATH}" "${COMPAT_VIRTUALENV_PATH}"
 fi
 
 if [ ! -e "${VIRTUALENV_PATH}/bin/pydoc" ]; then