CI: Fix AppImage build error

(cherry picked from commit 83425f6)

ci/azure-jobs-linux.yml

@@ -12,7 +12,7 @@ jobs:
       Ubuntu_1604_GCC:
         IMAGE: librepcb/librepcb-dev:ubuntu-16.04-1
       Ubuntu_1604_Qt_5_12_3_GCC:
-        IMAGE: librepcb/librepcb-dev:ubuntu-16.04-qt5.12.3-1
+        IMAGE: librepcb/librepcb-dev:ubuntu-16.04-qt5.12.3-2
         DEPLOY: true
       Ubuntu_1804_Clang:
         IMAGE: librepcb/librepcb-dev:ubuntu-18.04-1

ci/build_linux_appimage.sh

@@ -3,10 +3,15 @@
 # set shell settings (see https://sipb.mit.edu/doc/safe-shell/)
 set -euv -o pipefail
 
+# Manually specify icon to be used for the AppImage
+cp "./build/install/opt/share/icons/hicolor/scalable/apps/org.librepcb.LibrePCB.svg" "./build/install/org.librepcb.LibrePCB.svg"
+
+# Build CLI AppImage
 cp -r "./build/install" "./build/install-cli"
 mv -f "./build/install-cli/opt/bin/librepcb-cli" "./build/install-cli/opt/bin/librepcb"
 linuxdeployqt "./build/install-cli/opt/share/applications/org.librepcb.LibrePCB.desktop" -bundle-non-qt-libs -appimage
-mv ./LibrePCB-x86_64.AppImage ./LibrePCB-CLI-x86_64.AppImage
+mv ./LibrePCB-*-x86_64.AppImage ./artifacts/nightly_builds/librepcb-cli-nightly-linux-x86_64.AppImage
+
+# Build LibrePCB AppImage
 linuxdeployqt "./build/install/opt/share/applications/org.librepcb.LibrePCB.desktop" -bundle-non-qt-libs -appimage
-cp ./LibrePCB-x86_64.AppImage ./artifacts/nightly_builds/librepcb-nightly-linux-x86_64.AppImage
-cp ./LibrePCB-CLI-x86_64.AppImage ./artifacts/nightly_builds/librepcb-cli-nightly-linux-x86_64.AppImage
+cp ./LibrePCB-*-x86_64.AppImage ./artifacts/nightly_builds/librepcb-nightly-linux-x86_64.AppImage

ci/install_dependencies.sh

@@ -1,9 +1,7 @@
 #!/usr/bin/env bash
 
 QTIFW_VERSION="3.0.4"
-
 QTIFW_URL_BASE="https://download.qt.io/official_releases/qt-installer-framework/$QTIFW_VERSION"
-LINUXDEPLOYQT_URL="https://github.com/probonopd/linuxdeployqt/releases/download/5/linuxdeployqt-5-x86_64.AppImage"
 
 # Install dependencies on Linux
 if [ "$OS" = "linux" ]