Explicitly disable WebAssembly in HTML5 builds

Emscripten enables WebAssembly by default since version 1.38.1

platform/javascript/detect.py

@@ -91,6 +91,7 @@ def configure(env):
         env.Append(LINKFLAGS=['--compression', lzma_binpath + "," + lzma_decoder + "," + lzma_dec])
 
     env.Append(LINKFLAGS=['-s', 'ASM_JS=1'])
+    env.Append(LINKFLAGS=['-s', 'WASM=0'])
     env.Append(LINKFLAGS=['-s', 'EXTRA_EXPORTED_RUNTIME_METHODS="[\'FS\']"'])
     env.Append(LINKFLAGS=['--separate-asm'])
     env.Append(LINKFLAGS=['-O2'])