docker: ubuntu: Use SDL2

Do not test the deprecated API versions (see cabd3584).
Debian MXE MinGW cross images are already using SDL2.
Signed-off-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: NAlex Bennée <alex.bennee@linaro.org>

tests/docker/dockerfiles/ubuntu.docker

@@ -5,7 +5,7 @@ ENV PACKAGES flex bison \
     libusb-1.0-0-dev libiscsi-dev librados-dev libncurses5-dev libncursesw5-dev \
     libseccomp-dev libgnutls-dev libssh2-1-dev  libspice-server-dev \
     libspice-protocol-dev libnss3-dev libfdt-dev \
-    libgtk-3-dev libvte-2.91-dev libsdl1.2-dev libpng12-dev libpixman-1-dev \
+    libgtk-3-dev libvte-2.91-dev libsdl2-dev libpng12-dev libpixman-1-dev \
     libvdeplug-dev liblzo2-dev libsnappy-dev libbz2-dev libxen-dev librdmacm-dev libibverbs-dev \
     libsasl2-dev libjpeg-turbo8-dev xfslibs-dev libcap-ng-dev libbrlapi-dev libcurl4-gnutls-dev \
     libbluetooth-dev librbd-dev libaio-dev glusterfs-common libnuma-dev libepoxy-dev libdrm-dev libgbm-dev \
@@ -15,4 +15,4 @@ ENV PACKAGES flex bison \
 RUN apt-get update && \
     apt-get -y install $PACKAGES
 RUN dpkg -l $PACKAGES | sort > /packages.txt
-ENV FEATURES clang pyyaml
+ENV FEATURES clang pyyaml sdl2