[librsvg-oci-images] Forgot to fix the rustc images like in 163e7892ef76862967e60b7f990aeb2777b65965

[Jordan Petridis <jpetridis src gnome org>]

commit c05ba2442a77c11d208b7ba24caaa50944323833
Author: Jordan Petridis <jordanpetridis protonmail com>
Date:   Thu May 17 17:06:58 2018 +0300

    Forgot to fix the rustc images like in 163e7892ef76862967e60b7f990aeb2777b65965

 .gitlab-ci.yml | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 25adb83..550fe32 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -34,7 +34,8 @@ stages:
 .rustc_template: &rustc
     stage: rustc
     before_script:
-        - export IMAGE=${CI_REGISTRY}/${CI_PROJECT_NAMESPACE}/${CI_PROJECT_NAME}/rustc:${TAG_VERSION}
+        - export NAMESPACE="$(echo "${CI_PROJECT_NAMESPACE}" | tr A-Z a-z)"
+        - export IMAGE=${CI_REGISTRY}/${NAMESPACE}/${CI_PROJECT_NAME}/rustc:${TAG_VERSION}
         - export OCI_YML=rustc.yml
         - export DIR=rustc/
         - sed -e "s|@RUSTC_VERSION@|$RUSTC_VERSION|" rustc/rustc_template > rustc/rustc.yml