Update README.md

Include SQLCipher CFLAGS for build instructions.

Author: developernotes

README.md

@@ -143,6 +143,7 @@ In order to build `android-database-sqlcipher` from source you will need both th
 SQLCIPHER_ROOT=/some/path/to/sqlcipher-folder \
 OPENSSL_ROOT=/some/path/to/openssl-folder \
 SQLCIPHER_ANDROID_VERSION="4.4.2" \
+SQLCIPHER_CFLAGS="-DSQLITE_HAS_CODEC" \
 OPENSSL_ANDROID_LIB_ROOT=/some/path/for/android/native/lib/creation \
 make build-release
 ```