compile with -O, in response to a poor performance report from Domagoj

doc/index.html

@@ -224,7 +224,7 @@ regular <tt>rsa</tt> key for greatest compatibility.
 <h2>Change Log</h2>
 
 <ul>
-<li> <b>2019/09/XXX Version 24:</b> Fix crash with "Start on Open" on Android 9. New TV icon.
+<li> <b>2019/09/XXX Version 24:</b> Fix crash with "Start on Open" on Android 9. New TV icon.  Slightly faster.
 <li> <b>2019/09/21 Version 23:</b> Support Android TV.
 <li> <b>2019/09/01 Version 22:</b> Add broadcast intents for start and stop.
 <li> <b>2019/08/11 Version 21:</b> Fix restarting after a crash.  Fix SIGSEGV on some Android 9 devices.

jni/Android.mk

@@ -2,7 +2,7 @@ LOCAL_PATH := $(call my-dir)
 
 include $(CLEAR_VARS)
 
-LOCAL_CFLAGS    :=
+LOCAL_CFLAGS    := -O
 LOCAL_MODULE    := simplesshd-jni
 
 DROPBEAR_PATH := ../dropbear
@@ -485,7 +485,7 @@ include $(BUILD_SHARED_LIBRARY)
 
 include $(CLEAR_VARS)
 
-LOCAL_CFLAGS    := -Wall
+LOCAL_CFLAGS    := -Wall -O
 LOCAL_MODULE    := scp
 
 DROPBEAR_PATH := ../dropbear
@@ -503,7 +503,7 @@ include $(BUILD_EXECUTABLE)
 
 include $(CLEAR_VARS)
 
-LOCAL_CFLAGS    := -Wall
+LOCAL_CFLAGS    := -Wall -O
 LOCAL_MODULE    := sftp-server
 
 OPENSSH_PATH := ../openssh
@@ -533,7 +533,7 @@ include $(BUILD_EXECUTABLE)
 
 include $(CLEAR_VARS)
 
-LOCAL_CFLAGS    := -Wall
+LOCAL_CFLAGS    := -Wall -O
 LOCAL_MODULE    := rsync
 
 RSYNC_PATH := ../rsync
@@ -611,7 +611,7 @@ include $(BUILD_EXECUTABLE)
 
 include $(CLEAR_VARS)
 
-LOCAL_CFLAGS    := -Wall
+LOCAL_CFLAGS    := -Wall -O
 LOCAL_MODULE    := buffersu
 
 LOCAL_SRC_FILES := buffersu.c