CI: Don't force a particular libc++ version
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 4a1e6f9..47991d4 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -9,7 +9,7 @@
   - echo 'deb-src http://deb.debian.org/debian unstable main' >> /etc/apt/sources.list
   - apt-get update
   - apt-get build-dep --yes --no-install-recommends poppler
-  - apt-get install --yes --no-install-recommends ninja-build libcurl4-openssl-dev git ca-certificates locales libc++-7-dev libc++abi-7-dev clang libgtk-3-dev
+  - apt-get install --yes --no-install-recommends ninja-build libcurl4-openssl-dev git ca-certificates locales libc++-dev libc++abi-dev clang libgtk-3-dev
   - echo 'en_US.UTF-8 UTF-8' >> /etc/locale.gen
   - locale-gen