Rephrase server failure warning in Blaze User Manual

PiperOrigin-RevId: 162755817
diff --git a/site/docs/bazel-user-manual.html b/site/docs/bazel-user-manual.html
index fb725e7..75be04a 100644
--- a/site/docs/bazel-user-manual.html
+++ b/site/docs/bazel-user-manual.html
@@ -3561,8 +3561,8 @@
   fast rule about whether or not your script should use a server, but
   in general, the trade-off is between performance and reliability.
   The server mode makes a sequence of builds, especially incremental
-  builds, faster, but its behavior is more complex and prone to
-  failure.  We recommend in most cases that you use batch mode unless
+  builds, faster, but its behavior is more complex and more likely to
+  fail.  We recommend in most cases that you use batch mode unless
   the performance advantage is critical.
 </p>
 <p>