Remove "rpc" category from GetWarnings

No longer used after removing safe mode.

This function can likely be simplified more, but I'll leave that
for later to make this easy to review.

src/warnings.cpp

@@ -40,7 +40,6 @@ void SetfLargeWorkInvalidChainFound(bool flag)
 std::string GetWarnings(const std::string& strFor)
 {
     std::string strStatusBar;
-    std::string strRPC;
     std::string strGUI;
     const std::string uiAlertSeperator = "<hr />";
 
@@ -60,12 +59,12 @@ std::string GetWarnings(const std::string& strFor)
 
     if (fLargeWorkForkFound)
     {
-        strStatusBar = strRPC = "Warning: The network does not appear to fully agree! Some miners appear to be experiencing issues.";
+        strStatusBar = "Warning: The network does not appear to fully agree! Some miners appear to be experiencing issues.";
         strGUI += (strGUI.empty() ? "" : uiAlertSeperator) + _("Warning: The network does not appear to fully agree! Some miners appear to be experiencing issues.");
     }
     else if (fLargeWorkInvalidChainFound)
     {
-        strStatusBar = strRPC = "Warning: We do not appear to fully agree with our peers! You may need to upgrade, or other nodes may need to upgrade.";
+        strStatusBar = "Warning: We do not appear to fully agree with our peers! You may need to upgrade, or other nodes may need to upgrade.";
         strGUI += (strGUI.empty() ? "" : uiAlertSeperator) + _("Warning: We do not appear to fully agree with our peers! You may need to upgrade, or other nodes may need to upgrade.");
     }
 
@@ -73,8 +72,6 @@ std::string GetWarnings(const std::string& strFor)
         return strGUI;
     else if (strFor == "statusbar")
         return strStatusBar;
-    else if (strFor == "rpc")
-        return strRPC;
     assert(!"GetWarnings(): invalid parameter");
     return "error";
 }

src/warnings.h

@@ -15,7 +15,6 @@ bool GetfLargeWorkForkFound();
 void SetfLargeWorkInvalidChainFound(bool flag);
 /** Format a string that describes several potential problems detected by the core.
  * strFor can have three values:
- * - "rpc": get critical warnings, which should put the client in safe mode if non-empty
  * - "statusbar": get all warnings
  * - "gui": get all warnings, translated (where possible) for GUI
  * This function only returns the highest priority warning of the set selected by strFor.