wl12360: Fix escaping of special characters in replacement string

Author: ltangvald

gen_dockerfiles.sh

@@ -81,9 +81,9 @@ DEFAULT_LOG["8.0"]="console"
 # MySQL 8.0 supports a call to validate the config, while older versions have it as a side
 # effect of running --verbose --help
 declare -A VALIDATE_CONFIG
-VALIDATE_CONFIG["5.6"]="output=$(\"$@\" --verbose --help 2>&1 > /dev/null) || result=$?"
-VALIDATE_CONFIG["5.7"]="output=$(\"$@\" --verbose --help 2>&1 > /dev/null) || result=$?"
-VALIDATE_CONFIG["8.0"]="output=$(\"$@\" --validate-config) || result=$?"
+VALIDATE_CONFIG["5.6"]="output=\$(\"\$@\" --verbose --help 2>&1 > /dev/null) || result=\$?"
+VALIDATE_CONFIG["5.7"]="output=\$(\"\$@\" --verbose --help 2>&1 > /dev/null) || result=\$?"
+VALIDATE_CONFIG["8.0"]="output=\$(\"\$@\" --validate-config) || result=\$?"
 
 for VERSION in "${!MYSQL_SERVER_VERSIONS[@]}"
 do