Add compatibility for incomplete crashes from KSCrash (#127)

* Add compatibility for incomplete crashes from KSCrash

* Improve error output

* Add incomplete crashreport test

Author: HazAT

SentryTests/SentryCrashProbeTests.swift

@@ -240,5 +240,11 @@ class SentrySwiftCrashProbeTests: XCTestCase {
         XCTAssertEqual(event?.exceptions?.first?.value, "P16kaboom_exception")
     }
 
-    
+    func testIncomplete() { // Call abort()
+        let crashJSON = testHelper.readIOSJSONCrashFile(name: "incomplete")!
+        
+        let event = CrashReportConverter.convertReportToEvent(crashJSON)
+        
+        XCTAssertNotNil(event)
+    }
 }