Fix test failures. Handle full allocation case.

Author: markt-asf

java/org/apache/coyote/http2/Http2UpgradeHandler.java

@@ -815,8 +815,10 @@ int reserveWindowSize(Stream stream, int reservation, boolean block) throws IOEx
                                 stream.wait(writeTimeout);
                             }
                             // Has this stream been granted an allocation
+                            // Note: If the stream in not in this Map then the
+                            //       requested write has been fully allocated
                             int[] value = backLogStreams.get(stream);
-                            if (value[1] == 0) {
+                            if (value != null && value[1] == 0) {
                                 // No allocation
                                 // Close the connection. Do this first since
                                 // closing the stream will raise an exception