Use Regexp.union to escape dots in JDBC driver jar name matching

Regexp.new(ojdbc_jars.join("|")) treats "." in jar names as a wildcard,
so the classpath check could match unintended strings and skip loading
the actual driver. Regexp.union properly escapes special characters.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: yahonda

lib/plsql/jdbc_connection.rb

@@ -19,7 +19,7 @@
   ojdbc_jars << "ojdbc6.jar"  if java_major >= 6
   ojdbc_jars << "ojdbc5.jar"  if java_major == 5
 
-  if ENV_JAVA["java.class.path"] !~ Regexp.new(ojdbc_jars.join("|"))
+  if ENV_JAVA["java.class.path"] !~ Regexp.union(ojdbc_jars)
     # On Unix environment variable should be PATH, on Windows it is sometimes Path
     env_path = (ENV["PATH"] || ENV["Path"] || "").split(File::PATH_SEPARATOR)
     # Look for JDBC driver at first in lib subdirectory (application specific JDBC file version)