Change the right of travisci_builder_id_key in the .travis.yml

This is better there. Instructions to prepare the ssh should be in the
same place.

.travis.yml

@@ -4,6 +4,7 @@ sudo: required
 before_install:
 - openssl aes-256-cbc -K $encrypted_eba2f7543984_key -iv $encrypted_eba2f7543984_iv
   -in travis/travisci_builder_id_key.enc -out travis/travisci_builder_id_key -d
+- chmod 600 travis/travisci_builder_id_key
 cache: ccache
 install: travis/install_extra_deps.sh
 script: travis/compile_all.sh

travis/deploy.sh

@@ -4,7 +4,6 @@ set -e
 
 SSH_KEY=travis/travisci_builder_id_key
 
-chmod 600 ${SSH_KEY}
 
 BASE_DIR="BUILD_*/INSTALL"
 ./kiwix-deploy.py ${BASE_DIR} ${ARCHIVE_TYPE} \