If there are no sources, have a more sensible cap on the number of sources

jni/OpenAL/Alc/ALu.c

@@ -1061,7 +1061,7 @@ ALvoid aluMixData(ALCdevice *device, ALvoid *buffer, ALsizei size)
 			alc_max_sources = max;
 		}
     } else {
-    	alc_max_sources = MAX_SOURCES_LOW;
+    	alc_max_sources = MAX_SOURCES_START;
     }
 #else
 	aluMixDataPrivate(device, buffer,  size);

jni/OpenAL/include/config.h

@@ -16,6 +16,7 @@
 
 // For throttling AlSource.c
 #define MAX_SOURCES_LOW 1
+#define MAX_SOURCES_START 8
 #define MAX_SOURCES_HIGH 64
 #endif