fix dockerfile

Author: senekor

Dockerfile

@@ -12,15 +12,14 @@ RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y \
     libsass-dev \
     libssl-dev
 
-# Install the currently pinned toolchain with rustup
-COPY rust-toolchain /tmp/
+# Install the Rust toolchain with rustup
 ENV RUSTUP_VERSION="1.24.3"
 ENV RUSTUP_TRIPLE="x86_64-unknown-linux-gnu"
 ENV RUSTUP_SHA="3dc5ef50861ee18657f9db2eeb7392f9c2a6c95c90ab41e45ab4ca71476b4338"
 RUN curl "https://static.rust-lang.org/rustup/archive/${RUSTUP_VERSION}/${RUSTUP_TRIPLE}/rustup-init" >/tmp/rustup-init && \
     echo "${RUSTUP_SHA}  /tmp/rustup-init" | sha256sum --check && \
     chmod +x /tmp/rustup-init && \
-    /tmp/rustup-init -y --no-modify-path --default-toolchain $(cat /tmp/rust-toolchain)
+    /tmp/rustup-init -y --no-modify-path
 ENV PATH=/root/.cargo/bin:$PATH
 
 WORKDIR /build