Fix git clean call from working copy

Author: sergeiignatov

scripts/build-android/build-android

@@ -89,6 +89,9 @@ else
  exit 128
 fi
 
+# Build working copy of srt repository
+REPO_DIR="../.."
+
 for build_target in $BUILD_TARGETS; do
  LIB_DIR=$BASE_DIR/$build_target/lib
  JNI_DIR=$BASE_DIR/prebuilt/$build_target
@@ -102,7 +105,7 @@ for build_target in $BUILD_TARGETS; do
   cp $LIB_DIR/libmbedx509.so $JNI_DIR/libmbedx509.so
  fi
 
- git -C $BASE_DIR/srt clean -fd
- $SCRIPT_DIR/mksrt -n $NDK_ROOT -a $API_LEVEL -t $build_target -e $ENC_LIB -s ../.. -i $BASE_DIR/$build_target
+ git -C $REPO_DIR clean -fd -e scripts
+ $SCRIPT_DIR/mksrt -n $NDK_ROOT -a $API_LEVEL -t $build_target -e $ENC_LIB -s $REPO_DIR -i $BASE_DIR/$build_target
  cp $LIB_DIR/libsrt.so $JNI_DIR/libsrt.so
 done