ci+docs: CentOS renamed the PowerTools repo to lowercase

Change-Id: I3868d1763c5b9d060603e440627ad8990de3ae4e
diff --git a/.jenkins.d/00-deps.sh b/.jenkins.d/00-deps.sh
index 3b5228f..ce24355 100755
--- a/.jenkins.d/00-deps.sh
+++ b/.jenkins.d/00-deps.sh
@@ -34,7 +34,7 @@
     fi
 
 elif has CentOS-8 $NODE_LABELS; then
-    sudo dnf config-manager --enable PowerTools
+    sudo dnf config-manager --enable powertools
     sudo dnf -y install gcc-c++ libasan pkgconf-pkg-config python3 \
                         boost-devel openssl-devel sqlite-devel \
                         libpcap-devel
diff --git a/INSTALL.md b/INSTALL.md
index a4a325c..8e0cd24 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -22,7 +22,7 @@
 
     On CentOS and Fedora:
 
-        sudo dnf config-manager --enable PowerTools  # CentOS only
+        sudo dnf config-manager --enable powertools  # CentOS only
         sudo dnf install libpcap-devel
 
 ## Build Steps