Fix version numbers in main branch

This should have already happened, when `PHP-7.3.0` was branched.

Author: cmb69

Zend/zend.h

@@ -20,7 +20,7 @@
 #ifndef ZEND_H
 #define ZEND_H
 
-#define ZEND_VERSION "3.3.0-dev"
+#define ZEND_VERSION "3.3.1-dev"
 
 #define ZEND_ENGINE_3
 

main/php_version.h

@@ -2,7 +2,7 @@
 /* edit configure.ac to change version number */
 #define PHP_MAJOR_VERSION 7
 #define PHP_MINOR_VERSION 3
-#define PHP_RELEASE_VERSION 0
+#define PHP_RELEASE_VERSION 1
 #define PHP_EXTRA_VERSION "-dev"
-#define PHP_VERSION "7.3.0-dev"
-#define PHP_VERSION_ID 70300
+#define PHP_VERSION "7.3.1-dev"
+#define PHP_VERSION_ID 70301