README.md: Remove stray apostrophe

Change-Id: I236a3aa66824759bf23b4331a22fa1d9ec25c5bf
diff --git a/README.md b/README.md
index b635362..9361631 100644
--- a/README.md
+++ b/README.md
@@ -27,7 +27,7 @@
 
 You can clone from the official osmo-trx.git repository using
 
-        git clone https://gitea.osmocom.org/cellular-infrastructure/osmo-trx`
+        git clone https://gitea.osmocom.org/cellular-infrastructure/osmo-trx
 
 There is a web interface at <https://gitea.osmocom.org/cellular-infrastructure/osmo-trx>