fix(docker): legacy "ENV key value" format

Author: PauloASilva

VMs/Dockerfile

@@ -35,7 +35,7 @@ RUN useradd -d /home/bench -m -s /bin/bash bench
 RUN echo bench:bench | chpasswd
 
 RUN chown -R bench /owasp/
-ENV PATH /owasp/BenchmarkJava:$PATH
+ENV PATH=/owasp/BenchmarkJava:$PATH
 
 # start up Benchmark once, for 60 seconds, then kill it, so the additional dependencies required to run it are downloaded/cached in the image as well.
 # exit 0 is required to return a 'success' code, otherwise the timeout returns a failure code, causing the Docker build to fail.