ci: check mobile compilation in same step as RPC

Because we now build a docker image for the RPC compilation, we can save
some execution minutes if we run the mobile RPC and code compilation check in the
same step of the CI workflow.

.github/workflows/main.yml

@@ -28,10 +28,10 @@ env:
 
 jobs:
   ########################
-  # RPC compilation check
+  # RPC and mobile compilation check
   ########################
   rpc-check:
-    name: RPC compilation check
+    name: RPC and mobile compilation check
     runs-on: ubuntu-latest
     steps:
       - name: git checkout
@@ -55,6 +55,12 @@ jobs:
 
       - name: run check
         run: make rpc-check
+        
+      - name: build mobile RPC bindings
+        run: make mobile-rpc
+
+      - name: build mobile specific code
+        run: go build --tags="mobile" ./mobile
 
   ########################
   # check commits
@@ -156,38 +162,6 @@ jobs:
       - name: build release for all architectures
         run: make release
 
-  ########################
-  # mobile compilation
-  ########################
-  mobile-compile:
-    name: mobile compilation
-    runs-on: ubuntu-latest
-    steps:
-      - name: git checkout
-        uses: actions/checkout@v2
-
-      - name: go cache
-        uses: actions/cache@v1
-        with:
-          path: /home/runner/work/go
-          key: lnd-${{ runner.os }}-go-${{ env.GO_VERSION }}-${{ github.job }}-${{ hashFiles('**/go.sum') }}
-          restore-keys: |
-            lnd-${{ runner.os }}-go-${{ env.GO_VERSION }}-${{ github.job }}-${{ hashFiles('**/go.sum') }}
-            lnd-${{ runner.os }}-go-${{ env.GO_VERSION }}-${{ github.job }}-
-            lnd-${{ runner.os }}-go-${{ env.GO_VERSION }}-
-            lnd-${{ runner.os }}-go-
-
-      - name: setup go ${{ env.GO_VERSION }}
-        uses: actions/setup-go@v2
-        with:
-          go-version: '~${{ env.GO_VERSION }}'
-
-      - name: build mobile RPC bindings
-        run: make mobile-rpc
-
-      - name: build mobile specific code
-        run: go build --tags="mobile" ./mobile
-
   ########################
   # sample configuration check
   ########################