install silx from master instead of fix_is_absolute

ci/install_scripts.sh

@@ -5,7 +5,7 @@ function install_tomoscan(){
 }
 
 function install_silx(){
-    python -m pip install git+https://github.com/silx-kit/silx.git@fix_is_absolute
+    python -m pip install git+https://github.com/silx-kit/silx.git@master
 }
 
 function silx_version(){