[#1304] Addressed comments

Author: fxdupont

doc/sphinx/arm/hooks-ha.rst

@@ -594,7 +594,7 @@ list:
    commands to that server.
 
 -  ``basic-auth-user`` - specifies the user id for basic HTTP
-   authentication. If not specified or specified to the empty string
+   authentication. If not specified or specified as an empty string
    no authentication header will be added to HTTP transactions.
    Must not contain the colon (:) character.
 

doc/sphinx/arm/shell.rst

@@ -130,5 +130,5 @@ tool.
 
 .. note::
 
-   When using this tool with basic HTTP authentication please not forget
-   that command line arguments are not hidden to local users.
+   When using this tool with basic HTTP authentication please keep in
+   mind that command line arguments are not hidden to local users.

src/lib/http/basic_auth_config.h

@@ -16,7 +16,7 @@ namespace isc {
 namespace http {
 
 /// @brief Type of basic HTTP authentication credential and user id map,
-/// e.g. map["am9obmRvZTpzZWNyZXQx" = "johndoe".
+/// e.g. map["am9obmRvZTpzZWNyZXQx"] = "johndoe".
 ///
 /// The map is used to verify a received credential: if it is not in it
 /// the authentication fails, if it is in it the user id is logged.