Use ADD instead of wget

diff --git a/Dockerfile b/Dockerfile
index 2076d46..3a6df19 100644
--- a/Dockerfile
+++ b/Dockerfile

@@ -12,8 +12,7 @@
     libtool \
     m4 \
     net-tools \
-    pkg-config \
-    wget
+    pkg-config
 
 # OpenSSL
 ARG openssl_name=openssl-1.1.0h
@@ -29,7 +28,7 @@
 # IBM's Software TPM 2.0
 ARG ibmtpm_name=ibmtpm1119
 WORKDIR /tmp
-RUN wget "https://downloads.sourceforge.net/project/ibmswtpm2/$ibmtpm_name.tar.gz"
+ADD "https://downloads.sourceforge.net/project/ibmswtpm2/$ibmtpm_name.tar.gz" .
 RUN sha256sum $ibmtpm_name.tar.gz | grep ^b9eef79904e276aeaed2a6b9e4021442ef4d7dfae4adde2473bef1a6a4cd10fb
 RUN mkdir -p $ibmtpm_name
 RUN tar xvf $ibmtpm_name.tar.gz -C $ibmtpm_name