run-tests.sh: call php with -n argument

Related to https://github.com/nette/tester/commit/477114ec17826174c20abd226a1a4373b4609fa0
tests: Controls\CsrfProtection stores session in TEMP_DIR

Related to https://github.com/nette/nette/commit/084fb21d4d81fe508ba9bbbf383284739eff47e8
tests: skip tests when PDO extension is missing
Merge pull request #1283 from milo/fix-tests

Test fixes