Change source/target JDK to 1.4

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/dbcp/branches/TEST_DBCP_1_3_BRANCH@884737 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/pom.xml b/pom.xml
index 6df41d5..db5d6ed 100644
--- a/pom.xml
+++ b/pom.xml
@@ -215,8 +215,8 @@
 
   <properties>
     <!-- Target Java versions are actually 1.4, 1.5 and 1.6 -->
-    <maven.compile.source>1.5</maven.compile.source>
-    <maven.compile.target>1.5</maven.compile.target>
+    <maven.compile.source>1.4</maven.compile.source>
+    <maven.compile.target>1.4</maven.compile.target>
     <commons.componentid>dbcp</commons.componentid>
     <commons.release.version>1.2.2</commons.release.version>
     <commons.binary.suffix></commons.binary.suffix>