MINOR: fix typos in the examples files

To be more specific the error 500 example page and the
transparent_proxy.cfg page. For the later, it is all in the comments but
still user-visible as those are examples.
diff --git a/examples/errorfiles/500.http b/examples/errorfiles/500.http
index ebf7d47..9c3be96 100644
--- a/examples/errorfiles/500.http
+++ b/examples/errorfiles/500.http
@@ -4,6 +4,6 @@
 Content-Type: text/html

 

 <html><body><h1>500 Internal Server Error</h1>
-An internal server error occured.
+An internal server error occurred.
 </body></html>
 
diff --git a/examples/transparent_proxy.cfg b/examples/transparent_proxy.cfg
index 0ecb20d..b514ae3 100644
--- a/examples/transparent_proxy.cfg
+++ b/examples/transparent_proxy.cfg
@@ -39,11 +39,11 @@
 # /sbin/sysctl net.link.ether.ipfw=1
 # ipfw add 10 fwd localhost tcp from 192.168.0.40 80 to any in recv em0
 #
-# the above does the folowing:
+# the above does the following:
 # - load the ipfw kernal module
 # - set pf as the outer firewall to keep control of routing packets for example to route them to a non-default gateway
 # - enable ipfw
-# - set a rule to catches reply traffic on em0 comming from the webserver
+# - set a rule to catches reply traffic on em0 coming from the webserver
 #
 # --- Step 2 ---
 # To also make the client connection transparent its possible to redirect incomming requests to HAProxy with a pf rule: