Update Irrlicht and NDK

ci_install.sh

@@ -1,13 +1,24 @@
 #!/bin/bash -e
-ndk_version=r25c
+ndk_version=r26c
+ndk_version_n=26.2.11394342
 
 # Build tools and stuff
 sudo apt-get update
 sudo apt-get install -y wget unzip zip gcc-multilib make cmake
 
 # NDK
-wget --progress=bar:force "http://dl.google.com/android/repository/android-ndk-${ndk_version}-linux.zip"
-unzip -q "android-ndk-${ndk_version}-linux.zip"
-rm "android-ndk-${ndk_version}-linux.zip"
+if [ -d "/usr/local/lib/android/sdk/ndk/${ndk_version_n}" ]; then
+	echo "Found system-wide NDK"
+	ndkpath="/usr/local/lib/android/sdk/ndk/${ndk_version_n}"
+else
+	wget --progress=bar:force "http://dl.google.com/android/repository/android-ndk-${ndk_version}-linux.zip"
+	unzip -q "android-ndk-${ndk_version}-linux.zip"
+	rm "android-ndk-${ndk_version}-linux.zip"
+	ndkpath="$PWD/android-ndk-${ndk_version}"
+fi
+if ! grep -qF "${ndk_version_n}" "${ndkpath}/source.properties"; then
+	echo "NDK version mismatch"
+	exit 1
+fi
 
-printf 'export ANDROID_NDK="%s"\n' "$PWD/android-ndk-${ndk_version}" >env.sh
+printf 'export ANDROID_NDK="%s"\n' "${ndkpath}" >env.sh

scripts/Irrlicht.sh

@@ -1,5 +1,5 @@
 #!/bin/bash -e
-irrlicht_ver=66786d0059e9cf021c34c1de30540a45d928308c
+irrlicht_ver=1.9.0mt15
 png_ver=1.6.42
 jpeg_ver=3.0.2