Use double quotes

Author: GauthamBanasandra

dev-support/docker/Dockerfile_centos_7

@@ -67,7 +67,7 @@ RUN dnf install -y \
 # Install GCC 9.3.0
 ####
 # hadolint ignore=DL3003
-RUN mkdir -p /tmp/gcc /opt/gcc ${HOME}/.gcc \
+RUN mkdir -p /tmp/gcc /opt/gcc "${HOME}/.gcc" \
     && curl -L -s -S https://ftp.gnu.org/gnu/gcc/gcc-9.3.0/gcc-9.3.0.tar.gz  -o /tmp/gcc/gcc-9.3.0.tar.gz \
     && tar xzf /tmp/gcc/gcc-9.3.0.tar.gz --strip-components 1 -C /opt/gcc \
     && cd /opt/gcc || exit \