Replace dash/smart quotes in build_env/Dockerfile

Author: cataphract

build_env/Dockerfile

@@ -73,5 +73,5 @@ RUN apk add --no-cache pcre-dev pcre2-dev zlib-dev openssl-dev perl
 
 # Install Rust toolchain
 RUN apk add --no-cache curl
-RUN curl –proto ‘=https’ –tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -yq \
+RUN curl --proto '=https' –tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -yq \
   && ln -s ~/.cargo/bin/cargo /usr/bin/cargo