Update conf.py

Author: mcbarton

docs/source/conf.py

@@ -8,12 +8,12 @@
 
 if on_rtd:
     XEUS_CPP_ROOT = os.path.abspath('../..')
-    command_emscripten = 'cd ..;\
+    command_emscripten = 'cd ../..;\
                           mamba init;\
                           . /home/docs/.bashrc;\
                           mamba create -p $PWD -f environment-wasm-build.yml -y;\
                           mamba activate xeus-cpp-wasm-build;\
-                          mamba create -p $PWD -f environment-wasm-host.yml --platform=emscripten-wasm32;\
+                          CONDA_SUBDIR=emscripten-wasm32 mamba create -p $PWD -f environment-wasm-host.yml;\
                           mkdir build;\
                           cd build;\
                           export BUILD_PREFIX=$MAMBA_ROOT_PREFIX/envs/xeus-cpp-wasm-build;\