[FLINK-14459][python] Fix python module build hang problem

The latest conda installer may hang in some circumstances. We should specify a stable version instead of the latest.

This closes apache#9941.

flink-python/dev/lint-python.sh

@@ -144,8 +144,8 @@ function install_wget() {
 # some pakcages including checks such as tox and flake8.
 
 function install_miniconda() {
-    OS_TO_CONDA_URL=("https://repo.continuum.io/miniconda/Miniconda3-latest-MacOSX-x86_64.sh" \
-        "https://repo.continuum.io/miniconda/Miniconda3-latest-Linux-x86_64.sh")
+    OS_TO_CONDA_URL=("https://repo.continuum.io/miniconda/Miniconda3-4.7.10-MacOSX-x86_64.sh" \
+        "https://repo.continuum.io/miniconda/Miniconda3-4.7.10-Linux-x86_64.sh")
     print_function "STEP" "download miniconda..."
     if [ ! -f "$CONDA_INSTALL" ]; then
         download ${OS_TO_CONDA_URL[$1]} $CONDA_INSTALL_SH