Bump MSRV for net-tokio to 1.45 as tokio 1.0 req very recent rustc

.github/workflows/build.yml

@@ -13,8 +13,8 @@ jobs:
                      1.30.0,
                      # 1.34.2 is Debian stable
                      1.34.2,
-                     # 1.39.0 is MSRV for lightning-net-tokio and generates coverage
-                     1.39.0]
+                     # 1.45.2 is MSRV for lightning-net-tokio and generates coverage
+                     1.45.2]
         include:
           - toolchain: stable
             build-net-tokio: true
@@ -26,7 +26,7 @@ jobs:
             build-net-tokio: true
           - toolchain: beta
             build-net-tokio: true
-          - toolchain: 1.39.0
+          - toolchain: 1.45.2
             build-net-tokio: true
             coverage: true
     runs-on: ${{ matrix.platform }}
@@ -180,7 +180,7 @@ jobs:
   linting:
     runs-on: ubuntu-latest
     env:
-      TOOLCHAIN: 1.39.0
+      TOOLCHAIN: 1.45.2
     steps:
       - name: Checkout source code
         uses: actions/checkout@v2