fixes: lib path not set to fat libs (aka PREFIX)

buildcode/sequoia.code

@@ -15,7 +15,7 @@ build_ios()
 {
     cargo update
     rustup run nightly cargo update
-    NETTLE_PREGENERATED_BINDINGS="${NETTLE_BINDINGS}" PKG_CONFIG_ALLOW_CROSS=1 RUST_BACKTRACE=1 PKG_CONFIG_PATH=$OUTPUT_DIR/${ARCH}/lib/pkgconfig RUSTFLAGS="-L ${CURRENT_LIB_DIR}/lib" rustup run nightly cargo build --target ${TARGET} -p sequoia-openpgp-ffi --release -Z build-std=core,alloc,std
+    NETTLE_PREGENERATED_BINDINGS="${NETTLE_BINDINGS}" PKG_CONFIG_ALLOW_CROSS=1 RUST_BACKTRACE=1 PKG_CONFIG_PATH=$OUTPUT_DIR/${ARCH}/lib/pkgconfig RUSTFLAGS="-L ${PREFIX}/lib" rustup run nightly cargo build --target ${TARGET} -p sequoia-openpgp-ffi --release -Z build-std=core,alloc,std
     # copy artefacts
     cp "${SEQUOIA_DIR}/target/${TARGET}/release"/*.a "${CURRENT_LIB_DIR}/lib"
 }