conditionaly include "local.conf" from Makefile

for convenience reasons included from Makefile, added to gitignore..

.gitignore

@@ -16,3 +16,4 @@ esp-link.sdf
 espfs/mkespfsimage/mman-win32/libmman.a
 .localhistory/
 tools/
+local.conf

Makefile

@@ -8,6 +8,8 @@
 # `VERBOSE=1 make ...` will print debug info
 # `ESP_HOSTNAME=my.esp.example.com make wiflash` is an easy way to override a variable
 #
+# optional local configuration file
+-include local.conf
 # Makefile heavily adapted to esp-link and wireless flashing by Thorsten von Eicken
 # Lots of work, in particular to support windows, by brunnels
 # Original from esphttpd and others...