scripted-diff: Clarify "user agent" variable name

This change allows to the use of the `CLIENT_` namespace without
potential name clashes.

-BEGIN VERIFY SCRIPT-
sed -i "s/\<CLIENT_NAME\>/UA_NAME/g" $( git grep -l "CLIENT_NAME" ./src)
-END VERIFY SCRIPT-

src/clientversion.cpp

@@ -20,7 +20,7 @@ using util::Join;
  * for both bitcoind and bitcoin-qt, to make it harder for attackers to
  * target servers or GUI users specifically.
  */
-const std::string CLIENT_NAME("Satoshi");
+const std::string UA_NAME("Satoshi");
 
 
 #include <bitcoin-build-info.h>

src/clientversion.h

@@ -33,7 +33,7 @@ static const int CLIENT_VERSION =
                          +     100 * CLIENT_VERSION_MINOR
                          +       1 * CLIENT_VERSION_BUILD;
 
-extern const std::string CLIENT_NAME;
+extern const std::string UA_NAME;
 
 
 std::string FormatFullVersion();

src/init.cpp

@@ -1464,7 +1464,7 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
             return InitError(strprintf(_("User Agent comment (%s) contains unsafe characters."), cmt));
         uacomments.push_back(cmt);
     }
-    strSubVersion = FormatSubVersion(CLIENT_NAME, CLIENT_VERSION, uacomments);
+    strSubVersion = FormatSubVersion(UA_NAME, CLIENT_VERSION, uacomments);
     if (strSubVersion.size() > MAX_SUBVERSION_LENGTH) {
         return InitError(strprintf(_("Total length of network version string (%i) exceeds maximum length (%i). Reduce the number or size of uacomments."),
             strSubVersion.size(), MAX_SUBVERSION_LENGTH));