update submodule name

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "source"]
+	path = cpp-api
+	url = https://github.com/Vector35/binaryninja-api

binaryninjacore-sys/build.rs

@@ -44,7 +44,7 @@ fn link_path() -> PathBuf {
 }
 
 fn main() {
-    println!("cargo:rerun-if-changed=source/binaryninjacore.h");
+    println!("cargo:rerun-if-changed=cpp-api/binaryninjacore.h");
 
     //Cargo's output directory
     let out_dir = env::var("OUT_DIR").unwrap();
@@ -79,7 +79,7 @@ fn main() {
     let minimum_line = "#define BN_MINIMUM_UI_ABI_VERSION ";
     let mut current_version = "0".to_string();
     let mut minimum_version = "0".to_string();
-    let file = File::open("source/ui/uitypes.h").expect("Couldn't open uitypes.h");
+    let file = File::open("cpp-api/ui/uitypes.h").expect("Couldn't open uitypes.h");
     for line in BufReader::new(file).lines() {
         let line = line.unwrap();
         if let Some(version) = line.strip_prefix(current_line) {
@@ -90,7 +90,7 @@ fn main() {
     }
 
     bindgen::builder()
-        .header("source/binaryninjacore.h")
+        .header("cpp-api/binaryninjacore.h")
         .clang_arg("-std=c++17")
         .clang_arg("-x")
         .clang_arg("c++")