Try to fix tumbleweed install build (#11)

Takashi Matsuo · web-flow · commit 763c73147015 · 2019-07-18T14:20:41.000-04:00
diff --git a/ci/kokoro/install/Dockerfile.opensuse-tumbleweed b/ci/kokoro/install/Dockerfile.opensuse-tumbleweed
@@ -30,7 +30,7 @@ RUN zypper refresh && \
 
 # ```bash
 RUN zypper refresh && \
-    zypper install -y grpc-devel gzip libcurl-devel pkg-config tar wget
+    zypper install -y grpc-devel gzip libcurl-devel tar wget
 # ```
 
 FROM devtools AS install
