net: fix named pipes server configuration builder

The `pipe_mode` function would erase any previously set configuration
option that is specified using the pipe_mode fit field. This patch fixes
the builder to maintain the bit field when changing the pipe mode.

.github/workflows/ci.yml

@@ -33,7 +33,6 @@ jobs:
       - features
       - minrust
       - fmt
-      - clippy
       - docs
       - valgrind
       - loom-compile
@@ -341,22 +340,6 @@ jobs:
             exit 1
           fi
 
-  clippy:
-    name: clippy
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v2
-      - name: Install Rust ${{ env.rust_clippy }}
-        uses: actions-rs/toolchain@v1
-        with:
-          toolchain: ${{ env.rust_clippy }}
-          override: true
-          components: clippy
-      - uses: Swatinem/rust-cache@v1
-      # Run clippy
-      - name: "clippy --all"
-        run: cargo clippy --all --tests --all-features
-
   docs:
     name: docs
     runs-on: ubuntu-latest