Disambiguate I2NP and I2CP message headers (for ctags)

i2p2www/pages/site/docs/spec/i2cp.html

@@ -299,7 +299,7 @@ A basic summary of the I2CP protocol versions is as follows. For details, see be
 
 
 
-<h3 id="struct_header">I2CP message header</h3>
+<h3 id="struct_I2CPMessageHeader">I2CP message header</h3>
 <h4>Description</h4>
 <p>
   Common header to all I2CP messages, containing the message length and message type.

i2p2www/pages/site/docs/spec/i2np.html

@@ -90,7 +90,7 @@ see the NTCP and SSU transport documentation for details.
 The following structures are elements of multiple I2NP messages.
 They are not complete messages.
 
-<h3 id="struct_header">I2NP message header</h3>
+<h3 id="struct_I2NPMessageHeader">I2NP message header</h3>
 <h4>Description</h4>
 <p>
   Common header to all I2NP messages, which contains important information like a checksum, expiration date, etc.

i2p2www/pages/site/docs/spec/tunnel-message.html

@@ -236,7 +236,7 @@ Message ID:
        Optional, present if this message is the first of 2 or more fragments
           (i.e. if the fragmented bit is 1)
        An ID that uniquely identifies all fragments as belonging to a single message
-       (the current implementation uses the <a href="{{ site_url('docs/spec/i2np') }}#struct_header">I2NP Message ID</a>)
+       (the current implementation uses the <a href="{{ site_url('docs/spec/i2np') }}#struct_I2NPMessageHeader">I2NP Message ID</a>)
 
 Extended Options:
        2 or more bytes