OOM Crash log include size of allocation attempt. (#7670)

Since users often post just the crash log in github issues, the log
print that's above it is missing.
No reason not to include the size in the panic message itself.

(cherry picked from commit 0f741a9e2de355211667c0f2ad38f7bead686c28)

src/server.c

@@ -4911,7 +4911,8 @@ void loadDataFromDisk(void) {
 void redisOutOfMemoryHandler(size_t allocation_size) {
     serverLog(LL_WARNING,"Out Of Memory allocating %zu bytes!",
         allocation_size);
-    serverPanic("Redis aborting for OUT OF MEMORY");
+    serverPanic("Redis aborting for OUT OF MEMORY. Allocating %zu bytes!", 
+        allocation_size);
 }
 
 void redisSetProcTitle(char *title) {