[ci] Add libgcrypt to Docker image. (#3711)
As recommended in https://github.com/flutter/website/pull/5466
diff --git a/.ci/Dockerfile b/.ci/Dockerfile
index 14000e2..13fd48b 100644
--- a/.ci/Dockerfile
+++ b/.ci/Dockerfile
@@ -31,7 +31,7 @@
# Install Linux desktop build tool requirements.
RUN sudo apt-get install -y clang cmake ninja-build file pkg-config
# Install necessary libraries.
-RUN sudo apt-get install -y libgtk-3-dev libblkid-dev liblzma-dev
+RUN sudo apt-get install -y libgtk-3-dev libblkid-dev liblzma-dev libgcrypt20-dev
# Add repo for Google Chrome and install it
RUN wget -q -O - https://dl-ssl.google.com/linux/linux_signing_key.pub | sudo apt-key add -
