Use free rather than delete for malloc'd memory

src/client.cpp

@@ -1343,7 +1343,7 @@ void Client::ProcessData(u8 *data, u32 datasize, u16 sender_peer_id)
 								<<name << ": server ->"<<sha1_texture <<" client -> "<<digest_string<<std::endl;
 					}
 
-					delete(digest);
+					free(digest);
 				}
 			}
 

src/server.cpp

@@ -4307,7 +4307,7 @@ void Server::PrepareTextures() {
 				unsigned char *digest = sha1.getDigest();
 				std::string digest_string = base64_encode(digest, 20);
 
-				delete(digest);
+				free(digest);
 
 				// Put in list
 				this->m_Textures[tname] = TextureInformation(tpath,digest_string);