fix(example): remove warnings about libjpeg/libz

example/build.sh

@@ -1,2 +1,2 @@
 OBJ_DIR="/build/pdfium/out/Debug/obj"
-em++ -o "dist/pagecount.html" src/pagecount.c /build/pdfium/out/Debug/obj/libpdfium.a -lfxcrt -lfxge -lfdrm -lformfiller -lfxcodec -lbigint -lfpdfapi -lfx_agg -lfx_freetype -lfx_lcms2 -lfx_libopenjpeg -lfpdfdoc -lfxjs -ldl -lpthread -lrt -ljpeg -lz $OBJ_DIR/third_party/pdfium_base/address_space_randomization.o $OBJ_DIR/third_party/pdfium_base/page_allocator.o $OBJ_DIR/third_party/pdfium_base/partition_alloc.o $OBJ_DIR/third_party/pdfium_base/spin_lock.o -I/build/pdfium/public -L$OBJ_DIR -L$OBJ_DIR/third_party -s DEMANGLE_SUPPORT=1 --embed-file src/web-assembly.pdf 
+em++ -o "dist/pagecount.html" src/pagecount.c /build/pdfium/out/Debug/obj/libpdfium.a -lfxcrt -lfxge -lfdrm -lformfiller -lfxcodec -lbigint -lfpdfapi -lfx_agg -lfx_freetype -lfx_lcms2 -lfx_libopenjpeg -lfpdfdoc -lfxjs -ldl -lpthread -lrt $OBJ_DIR/third_party/pdfium_base/address_space_randomization.o $OBJ_DIR/third_party/pdfium_base/page_allocator.o $OBJ_DIR/third_party/pdfium_base/partition_alloc.o $OBJ_DIR/third_party/pdfium_base/spin_lock.o -I/build/pdfium/public -L$OBJ_DIR -L$OBJ_DIR/third_party -s DEMANGLE_SUPPORT=1 --embed-file src/web-assembly.pdf