Fix docker build with moved build.rs script

Release v0.34.0

Dockerfile

@@ -10,7 +10,7 @@ RUN echo 'fn main() { println!("Hello, world!"); }' >> src/main.rs
 COPY ./Cargo.lock ./Cargo.lock
 COPY ./Cargo.toml ./Cargo.toml
 # HACK: remove build-dependencies so we have at least some caching
-RUN head -n $(($(grep -n "\[build-dependencies\]" Cargo.toml | cut -f1 -d:) - 1)) Cargo.toml | sed '/build.rs/d' > \
+RUN head -n $(($(grep -n "\[build-dependencies\]" Cargo.toml | cut -f1 -d:) - 1)) Cargo.toml | sed '/src\/build.rs/d' > \
         Cargo.toml2  && rm Cargo.toml && mv Cargo.toml2 Cargo.toml
 # build to cache dependencies
 RUN cargo build --release
@@ -24,7 +24,6 @@ COPY ./.git ./.git
 # copy source code
 COPY ./static ./static
 COPY ./templates ./templates
-COPY ./build.rs ./build.rs
 COPY ./src ./src
 # build source code
 RUN cargo build --release