You may want to try using a slightly older version of apr; perhaps one from an OpenBSD packages site (somewhere like this OpenBSD Packages site?)
Note: any downloads and installations that you choose to make from sites like these are your decision. Please make sure to read related documentation for compatibility information, too, before making a decision about installing software in your environment!
Also, your version of OpenBSD may make a difference for what package site would be best to use... the OpenBSD packages site above is just an example of what these sites may look like.
For future reference, you can find more information about these sort of packages in the OpenBSD packages and ports documentation.