minor #36040 Fix Travis script (nicolas-grekas)

This PR was merged into the 5.0 branch.

Discussion
----------

Fix Travis script

| Q             | A
| ------------- | ---
| Branch?       | 5.0
| Bug fix?      | no
| New feature?  | no
| Deprecations? | no
| Tickets       | -
| License       | MIT
| Doc PR        | -

Commits
-------

ffef8fe7ae Fix Travis script

.travis.yml

@@ -266,6 +266,7 @@ install:
       run_tests () {
           set -e
           export PHP=$1
+          phpenv global $PHP
 
           if [[ !$deps && $PHP = 7.2 ]]; then
               tfold src/Symfony/Component/HttpClient.h2push "$COMPOSER_UP symfony/contracts && docker run -it --rm -v $(pwd):/app -v $(phpenv which composer):/usr/local/bin/composer -v /usr/local/bin/vulcain:/usr/local/bin/vulcain -w /app php:7.3-alpine ./phpunit src/Symfony/Component/HttpClient/Tests/CurlHttpClientTest.php --filter testHttp2Push"
@@ -275,7 +276,7 @@ install:
               echo -e "\\n\\e[33;1mIntermediate PHP version $PHP is skipped for pull requests.\\e[0m"
               return
           fi
-          phpenv global $PHP
+
           ([[ $deps ]] && cd src/Symfony/Component/HttpFoundation; cp composer.json composer.bak; composer config platform.ext-mongodb 1.6.0; composer require --dev --no-update mongodb/mongodb ~1.5.0)
           tfold 'composer update' $COMPOSER_UP
           tfold 'phpunit install' ./phpunit install