scripts: accept java 17-21

Motivation:
dCache master build with `--release=17` can run under java-21. Let
script reflect that.

Modification:
Update script to allow java 17-21 runtime.

Result:
accept java 17-21 for runtime

Acked-by: Karen Hoyos
Target: master
Require-book: no
Require-notes: yes

skel/share/lib/loadConfig.sh

@@ -54,11 +54,11 @@ findJava()
 
 isJavaVersionOk()
 {
-    # Should match 11-19, which will let java major versions 11 to 19 through.
+    # Should match 17-21 which will let java major versions 17 to 21 through.
     # Extract just the version number from 'java -version'
     version=$($JAVA -version 2>&1 | awk -F '"' '/version/ {print $2}')
     # Use grep to match against '^1[1-9].*$'
-    echo "$version" | grep -q "^1[1-9].*$"
+    echo "$version" | grep -q "^1[7-9].*$\|^2[0-1].*$"
     # Return result from the above grep (0 if successful, 1 if failed)
     return $?
 }
@@ -182,7 +182,7 @@ loadConfig()
 
 # Get java location
 if ! findJava || ! isJavaVersionOk; then
-    echo "Could not find usable Java VM. Please set JAVA_HOME to the path to Java 11"
+    echo "Could not find usable Java VM. Please set JAVA_HOME to the path to Java 17-21"
     echo "or newer."
     exit 1
 fi