set libzest.so location

Index: src/Plugin/ZynAddSubFX/ZynAddSubFX-UI-Zest.cpp
--- src/Plugin/ZynAddSubFX/ZynAddSubFX-UI-Zest.cpp.orig
+++ src/Plugin/ZynAddSubFX/ZynAddSubFX-UI-Zest.cpp
@@ -65,6 +65,8 @@ class ZynAddSubFXUI : public UI (public)
         handle = dlopen("@loader_path/libzest.dylib", RTLD_NOW | RTLD_LOCAL);
         if(!handle) // VST
             handle = dlopen("@loader_path/../Resources/libzest.dylib", RTLD_LAZY);
+#elif defined __OpenBSD__
+        handle = dlopen("/usr/local/share/zynaddsubfx/libzest.so", RTLD_LAZY);
 #else
         handle = dlopen("./libzest.so", RTLD_LAZY);
         if(!handle)
