Fix framerate throttling in Emscripten builds

Default com_maxfps to 0 under Emscripten. Under Emscripten the browser handles throttling the frame rate. Manual framerate throttling interacts poorly with Emscripten's browser-driven event loop.

code/qcommon/common.c

@@ -2741,7 +2741,14 @@ void Com_Init( char *commandLine ) {
 	// init commands and vars
 	//
 	com_altivec = Cvar_Get ("com_altivec", "1", CVAR_ARCHIVE);
+#ifdef EMSCRIPTEN
+	// Under Emscripten the browser handles throttling the frame rate.
+	// Manual framerate throttling interacts poorly with Emscripten's
+	// browser-driven event loop. So default throttling to off.
+	com_maxfps = Cvar_Get ("com_maxfps", "0", CVAR_ARCHIVE);
+#else
 	com_maxfps = Cvar_Get ("com_maxfps", "85", CVAR_ARCHIVE);
+#endif
 	com_blood = Cvar_Get ("com_blood", "1", CVAR_ARCHIVE);
 
 	com_logfile = Cvar_Get ("logfile", "0", CVAR_TEMP );