Don't add EAC to the demo if not building with EAC
diff --git a/contrib/single_file_transcoder/examples/emscripten.cpp b/contrib/single_file_transcoder/examples/emscripten.cpp
index dd20ea2..19eb8c3 100644
--- a/contrib/single_file_transcoder/examples/emscripten.cpp
+++ b/contrib/single_file_transcoder/examples/emscripten.cpp
@@ -980,6 +980,7 @@
 			: cTFBC1; // 2
 	}
 #endif
+#if BASISD_SUPPORT_ETC2_EAC_A8 || !defined(BASISD_SUPPORT_ETC2_EAC_A8)
 	/*
 	 * Then ETC2 (which may be incorrect).
 	 */
@@ -989,6 +990,7 @@
 			? cTFETC2  // 1
 			: cTFETC1; // 0
 	}
+#endif
 	/*
 	 * Finally ETC1, falling back on RGBA.
 	 *