.env: temporary switch to source-based C# node building

v3.8 of C# node is the first version that is going to have every module
in a single release build. Right now the format of release assets is not
known, hence Dockerfile.sharp is still out-of-date and will be updated
as soon as we have v3.8.0 published.

Ref. #175.

Signed-off-by: Anna Shaleva <[email protected]>

Author: AnnaShaleva

Diff for: .env

@@ -18,5 +18,5 @@ DC_MIXED_7_IR=.docker/ir/docker-compose.mixed.7.yml
 
 DF_GO=.docker/build/Dockerfile.golang
 DF_BENCH=.docker/build/Dockerfile.bench
-DF_SHARP=.docker/build/Dockerfile.sharp
-#DF_SHARP=.docker/build/Dockerfile.sharp.sources
+#DF_SHARP=.docker/build/Dockerfile.sharp
+DF_SHARP=.docker/build/Dockerfile.sharp.sources