MINOR: stats: also report the nice and number of calls for applets

Since applets are now part of the main scheduler, it's useful to report
their nice value and the number of calls to the applet handler, to see
where the CPU is spent.
diff --git a/src/stream.c b/src/stream.c
index 7ad84e9..9fdf662 100644
--- a/src/stream.c
+++ b/src/stream.c
@@ -2911,13 +2911,14 @@
 		}
 		else if ((tmpctx = objt_appctx(strm->si[0].end)) != NULL) {
 			chunk_appendf(&trash,
-			              "  app0=%p st0=%d st1=%d st2=%d applet=%s tmask=0x%lx\n",
+			              "  app0=%p st0=%d st1=%d st2=%d applet=%s tmask=0x%lx nice=%d calls=%u\n",
 				      tmpctx,
 				      tmpctx->st0,
 				      tmpctx->st1,
 				      tmpctx->st2,
 			              tmpctx->applet->name,
-				      tmpctx->thread_mask);
+			              tmpctx->thread_mask,
+			              tmpctx->t->nice, tmpctx->t->calls);
 		}
 
 		if ((cs = objt_cs(strm->si[1].end)) != NULL) {
@@ -2944,13 +2945,14 @@
 		}
 		else if ((tmpctx = objt_appctx(strm->si[1].end)) != NULL) {
 			chunk_appendf(&trash,
-			              "  app1=%p st0=%d st1=%d st2=%d applet=%s tmask=0x%lx\n",
+			              "  app1=%p st0=%d st1=%d st2=%d applet=%s tmask=0x%lx, nice=%d, calls=%u\n",
 				      tmpctx,
 				      tmpctx->st0,
 				      tmpctx->st1,
 				      tmpctx->st2,
 			              tmpctx->applet->name,
-				      tmpctx->thread_mask);
+			              tmpctx->thread_mask,
+			              tmpctx->t->nice, tmpctx->t->calls);
 		}
 
 		chunk_appendf(&trash,